bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of dynamic features in the walking videos of patients with adolescent idiopathic scoliosis based on moving entropy
Authors: Zhang Jiong , Han Yuhao , Yin Xiangjie , Wang Liang , Zhang Xueyi , Dong Keqiang
Published: January 2025

Adolescent idiopathic scoliosis (AIS), which typically occurs in patients between the ages of 10 and 18, can be caused by a variety of reasons, and no definitive cause has been found. Early diagnosis of AIS or timely recognition of progression is crucial for the prevention of spinal deformity and the reduction of the risk of surgery or postponement. However, it remains a significant challenge. The purpose of this study is to develop an easy-to-use, non-invasive, and portable method for early diagnosis of AIS. A new framework of moving entropy-based computer vision method is presented, which can determine the severity of AIS by analyzing patients’ walking videos. First, Alphapose system and direct linear transformation method are employed to estimate 3D keypoint coordinates. Then, the joint angle-based and joint distance-based dynamic network are constructed. Based on these works, the new measures called moving angle entropy and moving edge-weighted graph entropy are proposed and fused using canonical correlation analysis. Finally, the power spectral exponents of entropy sequences are calculated and used in recognizing the severity of AIS. A comparison with healthy subjects and statistical analysis for entropy values can provide effective information for quantifying AIS. The recognized results of our proposed method were also comparable with the clinical diagnosis of Cobb angle from imaging by a certified clinician.
Optimal scheduling strategy for electric vehicle charging and discharging in different types of buildings based on vehicle-to-building
Authors: Feng Zengxi , Zhang Xian , Li Gangting , Zhao Huaijun , Quan Wei
Published: January 2025

The application of vehicle-to-building (V2B) technology to integrate photovoltaic charging stations (PVCS) with smart building microgrids has gradually emerged as a new low-carbon operation model in the electric vehicle (EV) energy supply industry. The disordered integration of a large number of EVs into the power grid has caused numerous safety issues for building microgrids. Considering that buildings suitable for the construction of PVCS are primarily concentrated in residential, office, and commercial areas, this study proposes an optimized scheduling strategy for the charging and discharging of electric vehicles that considers different types of buildings. First, a PV-building-EV integrated system based on V2B is established. Probability distribution models of EV travel characteristics for different regions are obtained through actual data fitting, and unordered charging load curves for each region are derived by incorporating the Monte Carlo sampling method. On this basis, considering the interest of the building microgrids, PVCS operators, and EV users, a multi-objective optimization scheduling model for orderly EV charging and discharging based on V2B is established. Finally, the improved Non-dominated Sorting Genetic Algorithm II validates the model's effectiveness.
Mechanical response characteristics and cushioning of sealed airbags under different length–diameter ratios
Authors: Shen Yang , He Binbin , Hong Sirui , Cai Haiwei , Wu Bing , Lei Baiwei
Published: January 2025

In the event of a mine fire, rapidly constructing blast-resistant seals is one of the most effective measures to contain the disaster. This study conducted blast cushioning experiments on sealed airbags and numerical simulations by analysis system/Livermore software-dynamics (ANSYS/LS-DYNA), an explicit simulation software, to analyze the mechanical response characteristics and cushioning effectiveness of sealed airbags under different length-to-diameter ratios. The research results indicate that airbags with different length-to-diameter ratios all exhibit cushioning effects, and the airbag can recover its deformation after pressure release. As airbag length increases, vertical deformation along the pipeline appears, forming a radial compression failure mode. Stress concentrations are mostly located at the edges of the airbag, while arched structures can reduce the concentrated stress. Excessively long or short airbags significantly increase localized stress concentrations. The total energy absorbed by the airbag during cushioning shows a linear relationship with its length, and an energy absorption model for single-chamber airbags with varying length-to-diameter ratios was established. Under full-scale simulation conditions, the optimal length-to-diameter ratio range is 0.75:1. The reflected energy of shockwave encountering airbag is independent of airbag length and remains a fixed value when inflation pressure remains constant. These findings provide theoretical support for the design and application of explosion-resistant airbag.
Hundred-meter-scale MgB2 multi-filament wires with Cu stabilizer fabricated by internal Mg diffusion process
Authors: Yu Qihang , Yang Fang , Wang Qingyang , Wang Yiming , Wu Bo , Yan Guo , Feng Yong , Zhang Pingxiang
Published: January 2025

The high stability and current carrying properties of multi-filament long wires are fundamental to applying MgB2 superconducting materials. To ensure the current carrying properties and enhance stability, we utilized the internal Mg diffusion (IMD) process to fabricate different structures of Cu-stabilized, hundred-meter-scale MgB2 wires: 7-filament, 6 + 1-filament, 12 + 7-filament, 18 + 1-filament, 30 + 7-filament, and 36 + 1-filament. We characterized both the current carrying properties and the three-dimensional structure of these wires. The experimental results reveal that the current carrying properties strongly correlate with the integrity of the Nb barrier layer. In the 7-filament wire, the intact Nb barrier layer prevents contamination of the MgB2 superconducting phase, leading to a critical current density (J
c) of 4.16 × 105 A cm−2 at 4.2 K and 4 T. This study provides a foundation for the application of MgB2 superconducting wire.
Influence of atomic substitution on the superconducting critical temperature of scandium diboride: a computational study
Authors: Aladerah Bilal , Obeidat Abdalla
Published: January 2025

A computational analysis utilizing Density Functional Theory (DFT) is conducted to investigate the influence of atomic substitutions on the electronic, phononic, and superconducting properties of scandium diboride (ScB2). This investigation revealed significant enhancement in the material’s performance, notably through the doping of ScB2 with gallium and copper to produce the variants ScGaB and ScCuB. These modifications resulted in a substantial increase in the critical temperature (

T

C

), with the

T

C

of the copper-doped variant reaching up to 20.75 K. Additionally, detailed calculations of phonon dispersion relations and the density of states (DOS) along with the phonon density of states (PHDOS) were performed to evaluate the structural stability and explore the electronic hybridization between the atoms. These improvements in

T

C

, driven by strategic doping, represents a critical step in optimizing ScB2’s properties, making it more suitable for high-impact applications in advanced technological fields.
Cauchy matrix structure and the (2 + 1)-dimensional Date-Jimbo-Kashiwara-Miwa equation
Authors: Zhang Xinyuan , Li Chunxia , Zhou Zhen , Shen Tong
Published: January 2025

This paper applies the Cauchy matrix approach to construct the (2 + 1)-dimensional Date-Jimbo-Kashiwara-Miwa (DJKM) equation with σ
2 = ± 1 and study its integrability. By imposing certain dispersion relations on r and s of the Sylvester equation KM + ML = rs

T
, the DJKM equation is established through equations of the master function S
(i,j) = s

T

L

j

C(I + MC)−1
K

i

r. The connection of the τ function of the DJKM equation to Cauchy matrix approach is clarified. Moreover, Lax pair and exact solutions are derived for the DJKM equation systematically. It is interesting that the DJKM equation possesses diverse solutions. As examples, soliton solutions, breathers and interaction solutions are presented and illustrated under different choices of σ
2 = ± 1.
Temperature-controlled adjustable metamaterial terahertz demultiplexer design
Authors: Huang Yuanhao , Wang Yuanhui , Ma Xiaozhou , Gong Yibin , Zhang Xuanqi , Qu Zeng , Wang Jiayun
Published: January 2025

This paper introduces a novel temperature-controlled terahertz metamaterial demultiplexer that capitalizes on the phase transition characteristics of vanadium dioxide (VO2). The proposed demultiplexer is structured in three distinct layers: the top layer serves as a reflective layer, comprising a double-open resonance ring and a factory rectangular metal sheet; the middle layer is a polyimide dielectric isolation layer; and the bottom layer is a cross-shaped VO2 temperature-controlled layer. This design enables the effective separation of four distinct terahertz frequency bands: 0.72 THz, 1.11 THz, 0.98 THz, and 1.26 THz. Notably, the demultiplexer achieves high isolation levels exceeding −20 dB across all target frequencies, while maintaining an insertion loss of less than 1 dB. The device also exhibits extremely low insertion loss and high isolation properties, which are crucial for terahertz communication applications. Therefore, the presented design holds significant potential for application and development in the realm of terahertz communication technology, offering a viable solution for frequency separation in upcoming high-speed and broadband communication systems.
Effect of tracer size distribution on magnetic particle imaging performance
Authors: Azizi Ebrahim , Rezaei Bahareh , Mostufa Shahriar , Liang Shuang , Wang Yongqiang Andrew , Chugh Vinit Kumar , Wang Jian-Ping , Li Changzhi , Gómez-Pastora Jenifer , He Rui , Wu Kai
Published: January 2025

Magnetic particle imaging (MPI) is a tracer-based tomographic imaging technique utilized in applications such as lung perfusion imaging, cancer diagnosis, stem cell tracking, etc. The goal of translating MPI to clinical use has prompted studies on further improving the spatial-temporal resolutions of MPI through various methods, including image reconstruction algorithm, scanning trajectory design, magnetic field profile design, and tracer design. Iron oxide magnetic nanoparticles (MNPs) are favored for MPI and magnetic resonance imaging (MRI) over other materials due to their high biocompatibility, low cost, and ease of preparation and surface modification. For core–shell MNPs, the tracers’ magnetic core size and non-magnetic coating layer characteristics can significantly affect MPI signals through dynamic magnetization relaxations. Most works to date have assumed an ensemble of MNP tracers with identical sizes, ignoring that artificially synthesized MNPs typically follow a log-normal size distribution, which can deviate theoretical results from experimental data. In this work, we first characterize the size distributions of four commercially available iron oxide MNP products and then model the collective magnetic responses of these MNPs for MPI applications. For an ensemble of MNP tracers with size standard deviations of σ, we applied a stochastic Langevin model to study the effect of size distribution on MPI imaging performance. Under an alternating magnetic field (AMF), i.e., the excitation field in MPI, we collected the time domain dynamic magnetizations (M-t curves), magnetization-field hysteresis loops (M-H curves), point-spread functions (PSFs), and higher harmonics from these MNP tracers. The intrinsic MPI spatial resolution, which is related to the full width at half maximum (FWHM) of the PSF profile, along with the higher harmonics, serve as metrics to provide insights into how the size distribution of MNP tracers affects MPI performance.
Dynamics of chirped solitary waves: bifurcation and chaos in nonlinear chains with Morse potential
Authors: Abbagari Souleymanou , Houwe Alphonse , Akinyemi Lanre , Doka Serge Yamigno , Thomas Bouetou Bouetou
Published: January 2025

In this study, we explore the bifurcation of chirped waves in a nonlinear lattice incorporating the Morse potential. By applying the reductive perturbation method, we derive the generalized Kaup-Newell equation, representing the nonlinear system in a planar framework. Through qualitative analysis, homoclinic and heteroclinic orbits are revealed, confirming the propagation of solitary waves, including envelope solitons, dark solitons, kink, double-kink solutions, and periodic waves within the nonlinear chain. Furthermore, the introduction of an external force highlights chaotic behaviors, quasi-regular patterns, and time-dependent waveforms within the system. Notably, the qualitative characteristics exhibit extreme sensitivity to variations in the external force's amplitude. Additionally, the generalized Kaup-Newell model is derived from the nonlinear Klein–Gordon equation, providing further insight into the bifurcation behavior of solitary waves.
Entropy production in continuous systems with unidirectional transitions
Authors: Oliveira Mário J de
Published: January 2025

We derive an expression for the entropy production for stochastic dynamics defined on a continuous space of states containing unidirectional transitions. The expression is derived by taking the continuous limit of the stochastic dynamics on a discrete space of states and is based on an expression for the entropy production appropriate for unidirectional transitions. Our results show that the entropy flux is the negative result of the divergence of the vector field whose components are the rates at which a dynamic variable changes in time. For a Hamiltonian dynamical system, it follows from this result that the entropy flux vanish identically.
estiMAge: development of a DNA methylation clock to estimate the methylation age of single cells
Authors: Saßmannshausen Zoe , Blank Lisa , Solé-Boldo Llorenç , Lyko Frank , Raddatz Günter
Published: January 2025

Motivation

Since their introduction about 10 years ago, methylation clocks have provided broad insights into the biological age of different species, tissues, and in the context of several diseases or aging. However, their application to single-cell methylation data remains a major challenge, because of the inherent sparsity of such data, as many CpG sites are not covered. A methylation clock applicable on single-cell level could help to further disentangle the processes that drive the ticking of epigenetic clocks.

Results

We have developed estiMAge (“estimation of Methylation Age”), a framework that exploits redundancy in methylation data to substitute missing CpGs of trained methylation clocks in single cells. Using Euclidean distance as a measure of similarity, we determine which CpGs covary with the required CpG sites of an epigenetic clock and can be used as surrogates for clock CpGs not covered in single-cell experiments. estiMAge is thus a tool that can be applied to standard epigenetic clocks built on elastic net regression, to achieve bulk and single-cell resolution. We show that estiMAge can accurately predict the ages of young and old hepatocytes and can be used to generate single-cell versions of publicly available epigenetic clocks.

Availability and implementation

The source code and instructions for usage of estiMAge are available at https://github.com/DivEpigenetics/estiMAge
APOE4 impact on soluble and insoluble tau pathology is mostly influenced by amyloid-beta
Authors: Cicognola Claudia , Salvadó Gemma , Smith Ruben , Palmqvist Sebastian , Stomrud Erik , Betthauser Tobey , Johnson Sterling , Janelidze Shorena , Mattsson-Carlgren Niklas , Hansson Oskar , Pichet Binette Alexa
Published: January 2025

The APOE4 allele is the strongest genetic risk factor for sporadic Alzheimer’s disease (AD). While APOE4 is strongly associated with amyloid-beta (Aβ), its relationship with tau accumulation is less understood. Studies evaluating the role of APOE4 on tau accumulation showed conflicting results, particularly regarding the independence of these associations from Aβ load. In this study, we examined three independent longitudinal cohorts (BioFINDER-1, BioFINDER-2 and WRAP) in which participants had cross-sectional and longitudinal measures of tau tangles (tau-PET; temporal meta-ROI and entorhinal) or soluble p-tau (p-tau217), Aβ-PET and APOE genotype.

The study included a total of 1370 cognitively unimpaired (CU) and 449 mild cognitive impairment (MCI) subjects, followed longitudinally with tau-PET and p-tau217. APOE4 carriers accounted for 40.2-50% of the cohorts. Different linear regressions (cross-sectional) and linear mixed-effect models (longitudinal) with tau measures as outcomes were fitted to test the effect of APOE4 as independent predictor, as well as in combination with baseline Aβ load (including interaction). All models included age, sex and cognitive status as covariates.

We found no independent effects of the APOE4 carriership on insoluble tau in either cohort (BioFINDER-2 or WRAP), both on cross-sectional and longitudinal tau-PET in the temporal meta-ROI, when Aβ was present in the model (p=0.531-0.949). Aβ alone was the best predictor of insoluble tau accumulation, with no interaction between APOE4 and Aβ on tau-PET. In BioFINDER-2, there was a significant interaction between APOE4 and Aβ (b=0.166, p<0.001) in the entorhinal cortex at baseline. However, the interaction was not present in WRAP PET. No independent effects of the APOE4 carriership on baseline (p=0.683-0.708) and longitudinal (p=0.188-0.570) soluble p-tau217 were observed when Aβ was included in the model in BioFINDER-1 and WRAP. Similarly, no interaction between APOE4 and Aβ on soluble p-tau217 was observed. Mediation analysis revealed that Aβ load fully mediated most associations between APOE4 and tau (46-112%, either cross-sectional or longitudinal tau-PET or soluble p-tau217). In the largest cohort (BioFINDER-2), looking at APOE4 groups by number of ε4 alleles, we found an interaction between APOE4 homozygotes and Aβ on tau-PET levels at baseline and over time in the temporal meta-ROI, while in the entorhinal cortex this effect was observed only at baseline.

In conclusion, although APOE4 is strongly associated with Aβ aggregation, it seems to be minimally associated with longitudinal changes in soluble or insoluble p-tau levels at a given level of Aβ pathology, confirming the primacy of Aβ in driving tau pathology.
Biomarkers of disease progression in progressive supranuclear palsy for use in clinical trials
Authors: Marotta Cassandra , Sinclair Benjamin , O’Brien Terence J , Vivash Lucy
Published: January 2025

Progressive supranuclear palsy is a rare neurodegenerative disease with no current disease-modifying treatments approved. Longitudinal research and clinical trials for progressive supranuclear palsy are ongoing and require reliable measures which are sensitive to disease progression. Despite susceptibility to subjective limitations clinical and cognitive assessments are the most used instruments in therapeutic trials in progressive supranuclear palsy. The objective of this review is to identify measures which have been studied longitudinally as measures of progression and which are suitable for use as clinical trial endpoints. We reviewed the measures currently used as trial endpoints, identifying the clinical, cognitive, fluid and imaging measures which have previously been studied longitudinally, and discussing current diagnostic and emerging measures which are yet to be studied longitudinally but which may be sensitive to disease progression. We found that many fluid and imaging measures require further research to validate their use as longitudinal measures of change, including emerging measures which have not yet been studied specifically in progressive supranuclear palsy. We also summarise the sample size estimates required to detect changes in a 2-arm, 52-week therapeutic trial and found that specific MRI volumes require the smallest sample sizes to detect change.
Paying for home care out-of-pocket is common and costly across the income spectrum among older adults
Authors: Shen Karen , Yang Yang , Ornstein Katherine A , Shih Regina A , Reckrey Jennifer M
Published: January 2025

Many older adults with personal care needs rely on paid caregivers to remain in the community (“home care”). Those without Medicaid or private long-term-care insurance must pay out-of-pocket for care. We used the Health and Retirement Study to identify the prevalence and financial burden of paying for home care out-of-pocket in 2002–2018, by income and dementia status. Over 600 000 people with personal care needs paid out-of-pocket for home care in a given year, 45% of whom have dementia. The quantity and cost of this care were substantial for people with dementia in particular: 51% of those with dementia paying out-of-pocket for home care spent ≥$1000/month. While the probability of paying out-of-pocket for home care increased sharply with income, 52% of people paying out-of-pocket for home care had incomes below 200% of the federal poverty line; this group faced high financial burdens of care. Policies aimed at easing the financial burden of home care are essential, particularly for low-income individuals with dementia who experience the greatest financial burden.
Increasing competition, improving access, and lowering the cost of naloxone in California
Authors: Estus Emily , Figueroa Robin , Lee Helen , Pegany Vishaal , Tefera Lemeneh , Socal Mariana
Published: January 2025

Naloxone is an opioid antagonist that can reverse opioid overdoses and save lives. In 2023, the California Department of Health Care Access and Information mobilized its affordable drug manufacturing program, CalRx, to develop a more affordable naloxone nasal product that could help increase access for all Californians. Partnering with a new market entrant, CalRx offered a stable demand forecast for an initial 3-year agreement. In exchange, the selected manufacturer launched a new generic over-the-counter naloxone nasal product at a transparent price 40% lower than the state's previously contracted rate. In its first 6 months, internal calculations suggest that the CalRx generic naloxone has saved the state over $2.6 million, which could be used to provide more than 108 000 additional units of naloxone free of charge to communities across California. Overall generic naloxone prices declined by 22% in a single quarter immediately following CalRx entry. The CalRx experience has helped disrupt the naloxone market by increasing competition and reducing prices. The experience also demonstrates that leveraging states’ substantial purchasing power to negotiate lower prescription drug prices can have immediate market impact.
The post-gas expulsion coalescence of embedded clusters as an origin of open clusters
Authors: Zhou Jian-wen , Dib Sami , Kroupa Pavel
Published: January 2025

The mismatch between the mass function of the Milky Way’s embedded clusters (ECs) and that of open clusters (OCs) raises the question of whether each OC originates from a single EC. In this work, we explore a scenario in which OCs form as a result of post-gas expulsion coalescence of ECs within the same parental molecular cloud. We model this process using N-body simulations of ECs undergoing expansion due to gas expulsion. Our initial conditions are based on the observed spatial, kinematic, and mass distributions of ECs in three representative massive star-forming regions. Initially, ECs are isolated. After further expansion, interactions between ECs begin, mutually influencing their evolution. We examine this process as a function of gas expulsion time-scales, spatial separations between ECs, and their relative velocities. Our results demonstrate that, within a reasonable range of these parameters, the coalescence of ECs is robust and largely insensitive to initial conditions. The mass of ECs plays a critical role in the coalescence process. More massive ECs form stable gravitational cores, which greatly facilitate coalescence and help the resulting cluster resist expansion and Galactic tidal forces. Additionally, the number of ECs also enhances coalescence. The current mass distribution of clumps in the Milky Way suggests that directly forming massive ECs is challenging. However, the coalescence of multiple low-mass ECs can account for the observed parameter space of OCs in the Milky Way.
Ratio of Infections to COVID-19 Cases and Hospitalizations in the United States based on SARS-CoV-2 Seroprevalence Data, September 2021–February 2022
Authors: Deng Yangyang , Kim Yun , Bratcher Anna , Jones Jefferson M , Simuzingili Muloongo , Gundlapalli Adi V , Hagen Melissa Briggs , Iachan Ronaldo , Clarke Kristie E N
Published: January 2025

Background

Understanding the risk of hospitalization from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can guide effective public health interventions and severity assessments. This study calculated infection–hospitalization ratios (IHRs) and infection–case ratios (ICRs) to understand the relationship between SARS-CoV-2 infections, cases, and hospitalizations among different age groups during periods of Delta and Omicron variant predominance.

Methods

After calculating antinucleocapsid SARS-CoV-2 antibody seroprevalence using residual commercial laboratory serum specimens, 2 ratios were computed: (1) IHRs using coronavirus disease 2019 hospitalization data and (2) ICRs using Centers for Disease Control and Prevention surveillance data. Ratios were calculated across age groups (0–17, 18–49, 50–69, and ≥70 years) for 2 time periods (September–December 2021 [Delta] and December 2021–February 2022 [Omicron]).

Results

Pediatric IHRs increased from 76.7 during Delta to 258.4 during Omicron. Adult IHRs ranged from 3.0 (≥70 years) to 21.6 (18–49 years) during Delta and from 10.0 (≥70 years) to 119.1 (18–49 years) during Omicron. The pediatric ICR was lower during the Delta period (2.7) compared with the Omicron period (3.7). Adult ICRs (Delta: 1.1 [18–49 years] to 2.1 [70+ years]; Omicron: 2.2 [>70+ years] to 2.9 [50–69 years]) were lower than pediatric ICRs during both time periods.

Conclusions

All age groups exhibited a lower proportion of infections associated with hospitalization in the Omicron period than the Delta period; the proportion of infections associated with hospitalization increased with each older age group. A lower proportion of SARS-CoV-2 infections were associated with reported cases in the Omicron period than in the Delta period among all age groups.
The Game and Play of Utopia
Authors: Knight Mishael
Published: January 2025

The Utopians of Thomas More’s Utopia (1516) play two games, variants on chess. The first is a number game, but the second, where ‘the vices fight with the virtues in battle’ allows for a new way to interpret Utopia itself. By comparing it to popular moralizations of chess at the time, especially the Liber De Moribus Hominum et Officiis Nobilium Super Ludo Scacchorum of Jacobus de Cessolis, it becomes apparent that this game is used not only to replicate the distinctions between Utopian society and European, but also reflects the work Utopia. Utopia also constructs itself as a battle between virtues and vices, and this ludic structure indicates the work’s iterative nature and demonstrates how the work asks its readers to respond to it. What is more, recognizing Utopia itself as a game suggests that it is possible to further define the utopian genre as participation within this same tradition of game playing, exchanging the pieces on the board depending on the particular concerns of the author and context, but playing the same game. Thus, an understanding of utopian writing as a game emerges, alongside a demonstration of why Utopia remains such a pre-eminent example of the genre.
Valuing the Time of the Self-Employed
Authors: Agness Daniel , Baseler Travis , Chassang Sylvain , Dupas Pascaline , Snowberg Erik
Published: January 2025

People’s value of their own time is a key input in public policy evaluations—these evaluations should account for time taken away from work or leisure as a result of policy. Measuring this value for the self-employed is challenging, as, by definition, it is not priced by the market. Using rich choice data collected from farming households in western Kenya, we show that households exhibit non-transitive preferences. As a result, neither market wages nor standard valuation techniques correctly measure participants’ value of time. Using a structural model, we identify the behavioural wedges in participants’ choices and find that distortions appear when households exchange cash either for time or for goods. Our model estimates suggest that valuing the time of the self-employed at 60% of the market wage is a reasonable rule of thumb.
Evaluating the Adequacy of Central Line-Associated Bloodstream Infection As a Quality Measure: A Cross-Sectional Analysis at a Single Tertiary Care Center
Authors: Mathur Piyush , Naylor Amanda J. , Auron Moises , Beresian Jean , Tallman Alexandra , Griffith Allison , Seasholtz Kathleen , Manlapaz Mariel , Zacharyasz Katherine , Khatib Reem , Mishra Shreya , Haller Kathryn , Fraser Thomas , Holman Katherine
Published: January 2025

IMPORTANCE:

The current definition of central line-associated bloodstream infection (CLABSI) may overestimate the true incidence of CLABSI as it is often unclear whether the bloodstream infection (BSI) is secondary to the central line or due to another infectious source.

OBJECTIVES:

We aimed to assess the prevalence and outcomes of central CLABSI at our institution, to identify opportunities for improvement, appropriately direct efforts for infection reduction, and identify gaps in the CLABSI definition and its application as a quality measure.

DESIGN, SETTING, AND PARTICIPANTS:

Retrospective cross-sectional study of patients identified to have a CLABSI in the period 2018–2022 cared for at the value-based purchasing (VBP) units of a 1200-bed tertiary care hospital located in Cleveland, OH. Each CLABSI episode was assessed for relationship with central venous catheter (CVC), suspected secondary source of BSI, mortality associated with the CLABSI hospital encounter, and availability of infectious disease physician or primary physician documentation of infectious source.

MAIN OUTCOMES AND MEASURES:

CLABSI episodes were classified as CVC related, CVC unrelated, and CVC relationship unclear. Mortality during the same encounter as the CLABSI event was assessed as an outcome measure. Descriptive statistics were performed.

RESULTS:

A total of 340 CLABSI episodes occurred in adult patients in VBP units. Majority of the CLABSI, 77.5% (266), occurred in the ICU. Of the CLABSI analyzed, 31.5% (107) were classified as unrelated to the CVC; 25.0% (85) had an unclear source; 43% (148) were classified as CVC related. For CVC-related cases, Staphylococcus and Candida were the predominant organisms. For the CVC unrelated and unclear groups Enterococcus was most prevalent. The mortality rate was lowest among patients classified with a CVC-related BSI. The positive predictive value (PPV) of the Centers for Disease Control and Prevention CLABSI definition to predict a true CVC-related infection was found to be 58.0%.

CONCLUSIONS AND RELEVANCE:

The definition of CLABSI as a surrogate for catheter-related BSI is inadequate, with a PPV of 58.0% (43.1–67.6%). Efforts should be redirected toward revising the CLABSI definition and possibly reevaluating its criteria. Resources should be assigned to further investigate and systematically prevent BSIs from secondary sources while adhering to existing CLABSI prevention bundles.
Artificial Intelligence Scribe and Large Language Model Technology in Healthcare Documentation: Advantages, Limitations, and Recommendations
Authors: Mess Sarah A. , Mackey Alison J. , Yarowsky David E.
Published: January 2025

Artificial intelligence (AI) scribe applications in the healthcare community are in the early adoption phase and offer unprecedented efficiency for medical documentation. They typically use an application programming interface with a large language model (LLM), for example, generative pretrained transformer 4. They use automatic speech recognition on the physician–patient interaction, generating a full medical note for the encounter, together with a draft follow-up e-mail for the patient and, often, recommendations, all within seconds or minutes. This provides physicians with increased cognitive freedom during medical encounters due to less time needed interfacing with electronic medical records. However, careful proofreading of the AI-generated language by the physician signing the note is essential. Insidious and potentially significant errors of omission, fabrication, or substitution may occur. The neural network algorithms of LLMs have unpredictable sensitivity to user input and inherent variability in their output. LLMs are unconstrained by established medical knowledge or rules. As they gain increasing levels of access to large corpora of medical records, the explosion of discovered knowledge comes with large potential risks, including to patient privacy, and potential bias in algorithms. Medical AI developers should use robust regulatory oversights, adhere to ethical guidelines, correct bias in algorithms, and improve detection and correction of deviations from the intended output.
The Role of Positron Emission Tomography Imaging in Breast Implant Illness
Authors: Azahaf Siham , Spit Karlinde A. , de Blok Christel J.M. , Bult Peter , Nanayakkara Prabath W.B.
Published: January 2025

Background:

Explantation often alleviates symptoms in women with breast implant illness. However, persistent complaints in some cases may be linked to persistent silicone-induced inflammation from residual silicone particles. Positron emission tomography (PET) imaging could potentially detect this inflammation. This case series describes the PET findings in women with ongoing symptoms after explantation.

Methods:

A retrospective review was performed of cases from the silicone outpatient clinic at the Amsterdam University Medical Centers, the Netherlands. All women underwent PET imaging due to persistent systemic symptoms after explantation (n = 17) or replacement (n = 1).

Results:

Before PET imaging, silicone deposits were demonstrated in all 18 cases using ultrasound or magnetic resonance imaging. PET imaging revealed varying fluorodeoxyglucose avidity in axillary, parasternal, mediastinal, cervical, or supraclavicular lymph nodes and extranodal sites in all patients, up to 11 years after explantation. The median implantation time was 17 years, the average number of implant sets was 2, and the median time from explantation to PET was 2 years. In cases where biopsy was performed, silicone lymphadenitis with characteristic foreign body reaction was confirmed. The PET findings suggest that silicone residues can provoke inflammation even years after explantation. However, not all women with silicone residues may exhibit fluorodeoxyglucose-positive PET scans, indicating variability in susceptibility to silicone-induced inflammation.

Conclusions:

PET imaging may be a useful diagnostic tool for detecting silicone-induced inflammation in patients with persistent complaints after explantation. However, given inherent limitations, further research is warranted to fully assess its potential diagnostic utility in breast implant illness.
Systematical Theoretical Study of the Nonpoint Source Effects in Nuclear Medicine Shielding Calculation
Authors: Gu Tianliang
Published: January 2025

The objective of this note was to systematically study the effects from nonpoint radiation sources on the nuclear medicine imaging room or uptake room shielding design. The dose from a nonpoint source to a location at a certain distance to the center of the source was calculated. A correction factor could be applied to the dose calculated using a point source model with the same distance to compensate the nonpoint source effects. The correction factor was a function only depending on the source relative dimension, the ratio of the source’s geometric dimension to the distance. Theoretical and numerical calculation were performed to calculate the correction factor on a one-dimensional line source, two-dimensional circular disc source, three-dimensional sphere, and cylinder sources. Our study indicated that for large nuclear medicine imaging rooms, the point source model was a good approximation for shielding design. For a small uptake room, a nonpoint source correction may be considered to calculate the barrier thickness.
Inflammatory Markers as Predictors of Orbital Infection Severity
Authors: Gibbons Alison , Cherkas Elliot , Kaur Mannat , Dharssi Shazia , Elsharawi Radwa , Ashraf Davin C. , Li Emily
Published: January 2025

Purpose:

To assess the utility of inflammatory marker levels in defining orbital cellulitis (OC) severity.

Methods:

A retrospective cohort study was conducted at 2 tertiary care centers using a medical record search of billing codes from January 1, 2000 to January 1, 2023. Patients were categorized into 2 cohorts—uncomplicated OC and OC with complication [subperiosteal abscess (SPA), orbital abscess (OA), or cavernous sinus thrombosis (CST)]. Values at presentation of the following markers were recorded: absolute neutrophil count (ANC), white blood cell count (WBC), platelet count, C-reactive protein (CRP), and neutrophil-to-lymphocyte ratio (NLR). Logistic regression, controlled for immunosuppression and age, compared levels between patients with uncomplicated OC versus OC with complication, surgical versus nonsurgical management, and abnormal versus normal presenting and final vision.

Results:

A total of 785 patients—413 uncomplicated OC (52.6%) and 372 OC with complication (47.4%) (272 SPA [73.2%], 85 OA [22.8%], and 15 CST [4.0%])—met criteria. The sample was majority male (58.2%) and White (65.9%), with a mean age of 31.6 ± 26.4 years. Platelet count, ANC, WBC, and NLR levels were significantly higher in patients with complicated OC (p < 0.001). Levels of ANC, WBC, CRP, and NLR were significantly higher in surgical patients (p < 0.001). Higher levels of NLR and ANC were associated with worse visual acuity and an relative afferent pupillary defect at presentation (p = 0.006 and p = 0.032, respectively) but not at the final follow-up.

Conclusions:

Levels of NLR, ANC, and WBC at presentation may have clinical utility in identifying severe orbital infections and may aid management.
Magnetic Resonance Imaging Demonstrates Differences in Brow and Upper Eyelid Fat and Muscle Layers Between East Asians and Caucasians
Authors: Manta Alexandra I. , Demer Joseph L. , Goldberg Robert A.
Published: January 2025

Purpose:

To objectively quantify, in East Asians and Caucasians, the width and distribution of the retro-orbicularis oculi and frontalis fat (ROOF) pad, subcutaneous fat, and orbicularis oculi muscle (OOM) at the superior orbital rim margin as well as 5 mm superior and inferior to this point.

Methods:

Thirty adults were studied by high-resolution, surface coil MRI. In the quasi-sagittal image through the globe center, the ROOF, subcutaneous fat, and OOM thickness were measured anterior to the orbital septum, at 3 points: at the superior orbital rim, and 5 mm superior, and 5 mm inferior to the rim.

Results:

Seventeen subjects were of East Asian descent and 13 were Caucasian. Mean age (±standard deviation) was 49 (±16, range 18–72 years) and 53 (±17, range 29–80 years), respectively. Subcutaneous fat, OOM, and ROOF individual and total anteroposterior layer thickness at the superior orbital rim was similar between East Asians and Caucasians, with average ROOF 63% to 66% (4.5 ± 1.0, 4.7 ± 1.5 mm) of the width at the rim, and 33% to 34% (1.7 ± 0.7–1.8 ± 1.0 mm) 5 mm superiorly. In Caucasians, 12 of 13 patients (92%) had no measurable ROOF 5 mm inferior to the orbital rim. Values for Caucasians were significantly smaller than for East Asians 5 mm under the rim, where the East Asian eyelid layers anterior to the orbital septum averaged: subcutaneous fat 0.9 ± 0.4 mm, OOM 1.2 ± 0.3 mm, ROOF 1.8 ± 1.2 mm, and preaponeurotic fat 1.1 ± 0.9 mm. At the same level, the Caucasian eyelid measured: subcutaneous fat 0.6 ± 0.5 mm and OOM 1.4 ± 0.3 mm.

Conclusions:

Retro-orbicularis oculi and frontalis fat is the major contributor to the anteroposterior thickness of the eyelid at the level of the superior orbital rim in both East Asians and Caucasians. In East Asians, the ROOF comprises much of the total width inferior to the superior rim, whereas the Caucasian eyelid is mostly muscular. In Caucasians, ROOF is centered around the rim and extends intra-orbitally onto the roof as opposed to East Asians in which it continues inferiorly, into the upper eyelid. These anatomic variations explain some of the differences in surface anatomy between ethnic groups.
Early Use Experience of the Crescent Right Atrial Cannula for Neonatal Veno-Venous Extracorporeal Membrane Oxygenation
Authors: Sobolic Michael , Park Yujin , Gowda Sharada H. , Carr Nicholas R. , Chapman Rachel , Chi Annie , Dantes Goeto , Dariya Vedanta , Dirnberger Daniel R. , Fernandes Caraciolo J. , Hamrick Shannon , Joshi Swosti , Keene Sarah , Linden Allison , Makkar Abhishek , Menkiti Ogechukwu , Miquel-Verges Franscesca , Quinones-Cardona Vilmaris , Rao Rakesh , Rodriguez Ricardo J. , Seabrook Ruth , Sloan Patrick , Suttner Denise , Weems Mark F. , Lusk Leslie , Rintoul Natalie , DiGeronimo Robert , Gray Brian W. ,   CHNC ECMO Focus Group
Published: January 2025

Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is associated with fewer neurological complications and decreased mortality compared to veno-arterial (VA) ECMO in neonatal respiratory failure. The Crescent right atrial (RA) cannula is the only dual-lumen cannula for neonatal VV ECMO designed to have the tip in the right atrium. The purpose of this study is to describe the experience with early use of the Crescent RA cannula. We performed a retrospective cohort study of 58 neonates and infants cannulated from September 2021 through August 2023 at 15 institutions represented within the Children’s Hospital Neonatal Consortium (CHNC) ECMO Focus Group. Members provided information on patient characteristics, ECMO runs, complications, and outcomes. Data were analyzed with descriptive statistics. Imaging was used during cannulation in 79.3% of cases. Survival to discharge was 84.5%. There was one major cannula-related complication resulting in death. The most common complication was cannula malposition in 46.6% of patients, requiring surgical repositioning in 29.3% of the total cohort. Early use experience with the Crescent RA cannula suggests that it is effective and safe in most patients, but the cannula may require repositioning to achieve optimal ECMO support or if malpositioned. Based on these observations, we developed recommendations for cannulation and cannula surveillance.
Predictors of Nonutilization of Ex Vivo Perfused Donor Heart Allografts
Authors: Rekhtman David , Asher Michaela , Iyengar Amit , Song Cindy , Weingarten Noah , Shin Max , DePaolo John , Kim Samuel , Cevasco Marisa , Atluri Pavan
Published: January 2025

Despite the development of novel procurement technologies, an imbalance remains between the demand for and the availability of donor hearts. We aimed to identify donor characteristics predictive of nonutilization of hearts supported by ex vivo perfusion. A national database was used to identify ex vivo perfused hearts before September 30, 2023. Donors were stratified into cohorts of “Used” and “Discarded” based on final allocation. Logistic regressions were developed to identify predictors of nonutilization in both the ex vivo and non-ex vivo perfused hearts. Of 1,393 hearts supported with ex vivo perfusion, 154 (11%) were unused. Unused donors were older and had more diabetes and hypertension (p < 0.05). By multivariable logistic regression, reduced ejection fraction (7.10 [3.19–15.77], p < 0.001), coronary artery disease (6.27 [1.15–34.30], p = 0.034), and advanced age (3.25 [2.02–5.21], p < 0.001) were predictors of discard. Elevated body mass and prolonged ischemic times were only predictive of discard in the non-ex vivo perfused cohort. Among procured donor hearts supported by ex vivo perfusion, poor heart function, and donor comorbidities were identified as predictors of nonutilization. Increased appreciation for the role of these variables on post-transplantation outcomes will allow for the development of cost-effective strategies to expand the donor pool.
Outcomes after Ventral Hernia Repair with Concurrent Panniculectomy: A Large Database Review
Authors: Gossett Amy Gin , Leavitt Justin D , Hooks W Borden , Hope William W
Published: January 2025

Background:

Patients with large pannus and ventral hernias may benefit from undergoing panniculectomy performed concurrently with open ventral hernia repair (VHR-PAN). However, there has been concerns related to increase surgical site occurrences when adding a panniculectomy. This study aims to evaluate outcomes of open VHR with and without panniculectomy using a large hernia specific database.

Study Design:

The Abdominal Core Health Quality Collective (ACHQC) database was queried from 2012 to 2023 for patients who underwent VHR-only vs VHR-PAN. Patient and surgical characteristics were described and compared. Short-term outcomes including surgical site infection (SSI), surgical site occurrence (SSO), and SSO requiring procedural intervention (SSOPI) were compared. Patient reported outcomes (PROs) and hernia recurrence were compared at 1 year. Logistic regression was used to identify risks associated with the above outcomes.

Results:

There were 28,140 patients who underwent open VHR, 2108 where panniculectomy data were included (yes or no), and 870 who underwent VHR-PAN. Patients who underwent VHR-PAN were more likely to be female,78.3% vs 64.8% (p < 0.0001), have a BMI over 40, 21.0% vs 7.8% (p < 0.0001) with greater median hernia width, 10.0 [7.0, 15.0] vs 8.0 [3.0, 13.0] (p < 0.0001). In a matched analysis, there was no significant difference in SSI, SSO, SSOPI, or 1 year hernia recurrences rates in the VHR-PAN group (p<0.05).

Conclusion:

This study demonstrated that VHR with concurrent panniculectomy is not significantly associated with an increased risk of complications. Concurrent panniculectomy can be considered for selected patients needing VHR.