bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confined spaces in space: Cerebral implications of chronic elevations of inspired carbon dioxide and implications for long‐duration space travel
Authors: Carr Jay M. J. R. , Ainslie Philip N. , Day Trevor 
Published: January 2025

AbstractCerebrovascular regulation is critically dependent upon the arterial partial pressure of carbon dioxide (), owing to its effect on cerebral blood flow, tissue , tissue proton concentration, cerebral metabolism and cognitive and neuronal function. In normal environments and in the absence of pathology, at least over acute time frames, hypercapnia is usually managed readily via the respiratory chemoreflex arcs and/or acid–base buffering capacity, such that there is minimal impact on cerebrovascular and neurological function. However, in non‐normal environments, such as enclosed spaces, or with pathology, extended exposures to elevations in can be detrimental to cerebral health. Given the direct effect of protons on cellular function, even if pH is normalized, it is feasible that higher proton concentrations could still produce detrimental effects. Although it seems that humans can work safely in mildly hypercapnic environments for extended periods, chronic respiratory acidosis can cause bone demineralization, renal calcification, perinatal developmental abnormalities, systemic inflammation and impairments in cognitive function and visuomotor skills and can produce cerebral acidosis, potentially inducing sustained alterations in cerebral function. With the advancement of new initiatives in spaceflight, including proposed long‐duration missions to Mars, the study of the effects of chronic inspired CO2 on human health is relevant. In this review, we draw on evidence from preclinical, physiological and clinical research in humans to summarize the cerebral ramifications of prolonged and chronic exposures to elevated partial pressures of inspired CO2 and respiratory acidosis.
Nonlinear Mechanical Properties of Irregular Architected Materials
Authors: Wang Ruicheng , Bian Yijie , Liu Ke 
Published: January 2025

Abstract
Architected materials have received increasing attention due to their exotic mechanical properties including ultra-high stiffness-to-weight ratio, strength, energy absorption, and toughness. Typically, their mechanical properties and deformation behavior arise from the periodically tessellated unit cells. Although periodicity in conventional architected materials promises homogeneity and predictability in mechanical behaviors, it imposes a strong restriction on the design space of architected materials. Inspired by biomaterials, aperiodic and disordered designs significantly expand the design space and have been proven effective in controlling and optimizing linear elastic properties. Taking a step further, here we focus on the nonlinear properties of irregular lattice materials under large deformation, including the stress–strain curve and specific energy absorption. Such materials are generated by a nature-inspired virtual growth program that assembles predefined geometric building blocks in a stochastic yet controllable manner. The nonlinear properties are analyzed through quasi-static compression experiments and large-scale numerical simulations. Based on the well-agreed experimental and numerical results, through the lens of machine learning techniques, the nonlinear properties show a strong correlation with the appearance frequency of the building blocks and their local connectivity, regardless of the nondeterministic nature of the microstructures. A practical constitutive model is proposed for future developments such as generative design and engineering application. Our research offers valuable insights and serves as an inspiration for deeper exploration into the intricate structure–property relationships within materials with aperiodic and disordered microstructures.
Dynamics of an Electric Field Vulnerable Morpho-Elastic Biological Membranes
Authors: Agrawal Ankush , Khurana Aman , Kumar Deepak 
Published: January 2025

Abstract
This work presents the dynamic modeling and analysis of an electric field vulnerable morpho-elastic biological membranes. Such smart membranes combine electrical properties with active functionalities, creating flexible and responsive surfaces. A continuum physics-based electro-morpho-elastic model is developed to predict the dynamic response of the smart membrane and interrogate the impact of isotropic and anisotropic growth along with fiber orientations at different prestretches. The governing equation of motion for the membrane dynamics is derived by applying Newton’s second law. The findings of the model solutions offer an understanding of how the DC and AC dynamic actuation modes modify the nonlinear behavior of membranes. The free and forced vibrations are illustrated using the Poincaré map, phase diagrams, and time-history response. Notably, the steady oscillation around the stable equilibrium stretch, whose magnitude decreases with the enrichment in membrane anisotropy and fiber orientation, decreases with anisotropic growth. Additionally, the system energy rises with the anisotropy parameter and shifts from isotropic to anisotropic growth, decreasing with greater fiber orientation.
Determination of Ventilatory Thresholds Using Near-Infrared Spectroscopy in Recreational Endurance and CrossFit Athletes
Authors: Arnet Janik , Knaier Raphael , Schoch Raphael , D’Hulst Gommaar , Bruggisser Fabienne , Feldmann Andri , Leuenberger Rahel , Westerhuis Elena , Infanger Denis , Schmidt-Trucksäss Arno , Wagner Jonathan 
Published: January 2025

To define training zones, ventilatory thresholds (VTs) are commonly established by cardiopulmonary gas-exchange analysis during incremental exercise tests. Portable near-infrared spectroscopy (NIRS) devices have emerged as a potential tool for detecting these thresholds by monitoring muscle oxygenation. This study evaluated the accuracy of NIRS measurements to determine VTs or critical power (CP) based on muscle oxygen saturation and assesses the device’s consistency across 2 constant-load tests. Data from 2 cross-sectional studies involving trained recreational endurance athletes (26 from study 1) and CrossFit athletes (59 from study 2) were examined. Incremental ramp tests on a cycle ergometer were performed and followed by either a constant-load test (study 1) or a CP test (study 2). When comparing power output or heart rate between NIRS-derived breakpoints and VTs, weak to moderate agreement was found. Mean differences in power output and heart rate ranged from 16.8 to 22.4 W and 3.8 to 6.0 beats·min−1 at the first threshold and 27.4 to 31.2 W and 7.1 to 7.8 beats·min−1 at the second threshold. Comparing with CP, mean differences ranged from −0.4 to 0.4 W and −0.6 to 0.9 beats·min−1. Test–retest reliability showed moderate agreement, with a mean bias of 1.2 percentage points between constant-load tests. Thus, NIRS may not be accurate for determining VTs or CP during exercise due to limited agreement in power output or hear rate, notable variability on individual level, and moderate reproducibility.
Chlamydia trachomatis
impairs T cell priming by inducing dendritic cell death
Authors: Mao Haitong , Dumas Eric K. , Starnbach Michael N. 
Published: January 2025

ABSTRACT

The lack of effective adaptive immunity against
Chlamydia trachomatis
leads to chronic or repeated infection and serious disease sequelae. Dendritic cells (DCs) are professional antigen-presenting cells that are crucial for the activation of T cells during
C. trachomatis
infection. cDC1s and cDC2s are the two main DC subsets responsible for T cell priming, but little is known about how
C. trachomatis
affects their ability to prime T cells. Using a mouse model of infection, we found that
C. trachomatis
uptake reduced the viability of cDC1s and cDC2s both
in vitro
and
in vivo
, with cDC1s experiencing more death. DC death was mainly due to apoptosis and is alleviated in
Casp3/7
or
Bak1/Bax
knockout DCs. In addition, we observed that
C. trachomatis
-specific CD8+ T cells were preferentially activated by cDC1s. Reduction in DC viability by
C. trachomatis
impaired the ability of infected DCs to activate T cells upon co-culture, although in the case of CD8+ T cell priming, controlling for viability was insufficient to fully rescue the defect. RNA sequencing of DCs from infected mice showed upregulation of cell death pathways, supporting our observations of DC death caused by
C. trachomatis
. Finally, we validated our findings with human DCs
in vitro
, observing
C. trachomatis
-induced cell death. These results indicate that
C. trachomatis
may evade the adaptive immune system by directly inducing cell death in DCs.
Recent progress in proteins regulating the germination of
Bacillus subtilis
spores
Authors: Zhang Tianyu , Gong Ziqi , Zhou Bing , Rao Lei , Liao Xiaojun 
Published: January 2025

ABSTRACT

Bacterial spores can remain dormant for years, but they maintain the ability to recommence life through a process termed germination. Although spore germination has been reviewed many times, recent work has provided novel conceptual and molecular understandings of this important process. By using
Bacillus subtilis
as a model organism, here we thoroughly describe the signal transduction pathway and events that lead to spore germination, incorporating the latest findings on transcription and translation that are likely detected during germination. Then, we comprehensively review the proteins associated with germination and their respective functions. Notably, the typical germinant receptor GerA and the SpoVAF/FigP complex have been newly established as channels for ions release at early stage of germination. Moreover, given that germination is also affected by spore quality, such as molecular cargo, we collect the data about the proteins regulating sporulation to affect spore quality. Specifically, RocG-mediated glutamate catabolism during sporulation to ensure spore quality; GerE-regulated coat protein expression, and CotH-modified coat protein by phosphorylation to ensure normal coat assembly; and RNase Y-degraded RNA in newly released spores to promote dormancy. The latest progress in our understanding of these germination proteins provides valuable insights into the mechanism underlying germination.
Functions of nitroreductases in mycobacterial physiology and drug susceptibility
Authors: Eke Ifeanyichukwu E. , Abramovitch Robert B. 
Published: January 2025

ABSTRACT

Tuberculosis is a respiratory infection that is caused by members of the
Mycobacterium tuberculosis
complex, with
M. tuberculosis
(Mtb) being the predominant cause of the disease in humans. The approval of pretomanid and delamanid, two nitroimidazole-based compounds, for the treatment of tuberculosis encourages the development of more nitro-containing drugs that target Mtb. Similar to the nitroimidazoles, many antimycobacterial nitro-containing scaffolds are prodrugs that require reductive activation into metabolites that inhibit the growth of the pathogen. This reductive activation is mediated by mycobacterial nitroreductases, leading to the hypothesis that these nitroreductases contribute to the specificity of the nitro prodrugs for mycobacteria. In addition to their prodrug-activating activities, these nitroreductases have different native activities that support the growth of the bacteria. This review summarizes the activities of different mycobacterial nitroreductases with respect to their activation of different nitro prodrugs and highlights their physiological functions in the bacteria.
Development and validation of a risk prediction model related to inflammatory and nutritional indexes for postoperative pulmonary infection after radical colorectal cancer surgery
Authors: Han Jingxiang , Yao Tian , Gao Linna , Gao Huiyang , Chen Yuhao , Wang Yanli , Cao Yinglei , Liu Chengfei , Qiu Fubin , Jia Kai , Huang He 
Published: January 2025

ObjectiveTo develop and validate a risk prediction model related to inflammatory and nutritional indexes for postoperative pulmonary infection (POI) after radical colorectal cancer (CRC) surgery.DesignCross-sectional study.ParticipantsThis study analysed 866 CRC patients after radical surgery at a tertiary hospital in China.MethodsUnivariable and multivariable logistic regression (LR) analyses were used to explore influence factors of POI. Predictive models were constructed using LR, random forest, support vector machine, K-nearest neighbours, naive Bayes and XGBoost. The LR model was used to generate a nomogram for POI prediction. The discrimination and calibration of the nomogram were assessed using receiver operating characteristic (ROC) curves and calibration curves. The contributions of inflammatory and nutritional indexes to the nomogram were evaluated through Net Reclassification Improvement and integrated discrimination improvement, while clinical practicability was assessed using decision curve analysis.Main outcome measuresPOI during hospitalisation.ResultsIndependent factors identified from multivariable LR for prediction POI included age, respiratory disease, Systemic Inflammation Response Index, albumin-to-globulin ratio, operative method and operative duration. The LR model demonstrated the best performance, with an area under the ROC curve of 0.773 (95% CI: 0.674 to 0.872). The nomogram has good differentiation ability, calibration and net benefit. Incorporating inflammatory and nutritional indexes into the nomogram enhanced predictive value compared with models excluding either factor.ConclusionThe nomogram related to inflammatory and nutritional indexes may represent a promising tool for predicting POI after radical surgery in CRC patients.
On the analytical solution of the Schrödinger equation in ellipsoidal coordinates with constant potential
Authors: Mahareeq A.S. , Barghouthi I.A. , Atawnah Q.S. 
Published: January 2025

This paper solves the Schrödinger equation in confocal ellipsoidal coordinates under a constant potential. An auxiliary approach is introduced to separate the equation, which allows for the analytical derivation of energy levels using a series solution method. The results show that the four types of ellipsoidal harmonics lead to the same energy expressions. The energy levels are analyzed in terms of their dependence on the geometrical properties of the coordinates and their degeneracy patterns. This study highlights the role of ellipsoidal geometry in defining energy spectra and demonstrates its usefulness for describing quantum systems with non-spherical symmetry. The findings are relevant to diatomic molecules, quantum chemistry, and nanoscale physics, particularly nanorods. The method provides a foundation for future work on more complex potentials, which could extend the range of problems addressed using this approach.
Generative Artificial Intelligence Responses to Common Patient-Centric Hand and Wrist Surgery Questions: A Quality and Usability Analysis
Authors: PAUTLER Benjamin , MARCHESE Charles , SWANCUTT Makayla , BEUTEL Bryan G. 
Published: January 2025

Background: Due to the rapid evolution of generative artificial intelligence (AI) and its implications on patient education, there is a pressing need to evaluate AI responses to patients’ medical questions. This study assessed the quality and usability of responses received from two prominent AI platforms to common patient-centric hand and wrist surgery questions. Methods: Twelve commonly encountered hand and wrist surgery patient questions were inputted twice into both Gemini and ChatGPT, generating 48 responses. Each response underwent a content analysis, followed by assessment for quality and usability with three scoring tools: DISCERN, Suitability Assessment of Materials (SAM) and the AI Response Metric (AIRM). Statistical analyses compared the features and scores of the outputs when stratified by platform, question type and response order. Results: Responses earned mean overall scores of 55.7 (‘good’), 57.2% (‘adequate’) and 4.4 for DISCERN, SAM and AIRM, respectively. No responses provided citations. Wrist question responses had significantly higher DISCERN (p < 0.01) and AIRM (p = 0.02) scores compared to hand responses. Second responses had significantly higher AIRM (p < 0.01), but similar DISCERN (p = 0.76) and SAM (p = 0.11), scores compared to the first responses. Gemini’s DISCERN (p = 0.04) and SAM (p < 0.01) scores were significantly higher than ChatGPT’s corresponding metrics. Conclusions: Although responses are generally ‘good’ and ‘adequate’, there is variable quality with respect to platform used, type of question and response order. Given the diversity of publicly available AI platforms, it is important to understand the quality and usability of information patients may encounter during their search for answers to common hand and wrist surgery questions. Level of Evidence: Level IV (Therapeutic)
Angiogenesis and Axonal Elongation in Decellularised Nerve Grafts Depend on the Surrounding Vascular Environment
Authors: TANIMOTO Kaguna , KODAMA Akira , KUNISAKI Atsushi , MUNEMORI Masaru , KAMEI Naosuke , ADACHI Nobuo 
Published: January 2025

Background: Decellularised nerve transplantation has limited therapeutic efficacy for peripheral nerve injuries. In this study, we tested the hypothesis that nerve regeneration can be promoted by increasing blood circulation to the decellularised nerve through the surrounding blood-flow environment. Methods: We transplanted 20 mm decellularised nerves into sciatic nerve defects in Sprague–Dawley rats (female, 12 weeks old). In the intramuscular group, the decellularised nerve was implanted into the biceps femoris muscle and covered with the muscle to provide blood circulation. In the avascular group, the decellularised nerve was sutured to the sciatic nerve and the surrounding nerve bed was cauterised to create a non-bleeding field. In the intramuscular without repair group, the decellularised nerve was implanted in the biceps femoris muscle, but not sutured to the sciatic nerve. Axonal elongation and angiogenesis were evaluated immunohistochemically using anti-neurofilament, anti-S100 and anti-CD31 antibodies in sagittal and transverse sections of the nerve 3 weeks later. Results: In the intramuscular group, the number of neurofilaments per unit area and S100 were higher than those in the other groups (p < 0.05). CD31 staining was predominant in the intramuscular group. Axial images of the nerves confirmed the localisation of CD31-positive cells, and positive cells were found in the centre of the decellularised nerves in the intramuscular group. Conclusions: Decellularised nerve grafts wrapped with vascular-rich tissue promoted nerve regeneration by enhancing angiogenesis in transplanted nerve grafts and preventing ischemia in the centre of the nerve graft.
Counter‐Example to Diaby’s et al. Linear Programming Solution to the Traveling Salesman Problem
Authors: Hofman Radosław 
Published: January 2025

This article presents a method of constructing counter‐examples and a complete counter‐example to the linear programming model alleged to be the solution to the traveling salesman problem. The counter‐example is checked against the model proposed by Diaby et al. However, it applies to all similar formulations of the TSP problem.Although the model in question was published in 2006, and there were several discussions regarding its correctness, the counter‐example was never presented.The presented counter‐example is a regular graph, and the aim was not to have an example with the least possible size; therefore, the focus was on clarity. The counter‐example has, therefore, 366 nodes in two main clusters, each node (in the main part) having exactly four connections to other nodes in the cluster.
Demographic and Clinical Characteristics of Patients With Charcot Neuro‐Osteoarthropathy in People With Diabetes Mellitus in Six Countries: A Multicenter Observational Study From 1996 to 2022
Authors: Jude E. B. , Siafarikas C. , Rastogi A. , Bem R. , Tankova T. , Kong M.-F. , LaFontaine J. , Pappachan J. , Tentolouris N. 
Published: January 2025

Aim: To describe the demographic and clinical characteristics of patients with Charcot neuro‐osteoarthropathy (CNO) and to examine for differences between participants with Type 1 diabetes mellitus (DM) (T1DM) and Type 2 diabetes mellitus (T2DM).Materials and Methods: Multicenter observational study in eight diabetic foot clinics in six countries between January 1, 1996, and December 31, 2022. Demographic, clinical, and laboratory parameters were obtained from the medical records. Analyses were performed using parametric or nonparametric statistical tests for variables with normally or nonnormally distributed values, respectively. Comparisons of the qualitative data were performed using the chi‐square test.Results: Seven hundred seventy‐four patients with DM and CNO were included. The mean age at diagnosis of CNO was 54.5 ± 11.7 years, and the median (interquartile range (IQR)) diabetes duration at diagnosis of CNO was 15 (10–22) years. Among participants, 71.8% (n = 546) were male and 83.2% (n = 634) had T2DM. Neuropathy was present in 91.7% (n = 688), retinopathy in 60.2% (n = 452), and nephropathy in 45.2% (n = 337). Subjects with T1DM, compared to T2DM, were diagnosed with CNO at a younger age (46.9 ± 11.0 vs. 57.9 ± 10.2 years, p < 0.001), had longer diabetes duration (median value (IQR): 29.0 (21.0–38.0) vs. 14.0 (8.0–20.0) years, p < 0.001), and had more often microvascular complications (neuropathy, 95.2% in T1DM vs. 87.4% in T2DM, p = 0.006; retinopathy, 83.3% vs. 55.4%, p < 0.001; and nephropathy 67.5% vs. 40.5%, p < 0.001).Conclusions: CNO is predominant in males, occurs in long‐standing DM, and is often accompanied by microvascular complications. People with T1DM, compared to those with T2DM, are affected at a younger age, have longer diabetes duration, and have more often microvascular complications.
Analysis of Urban Indian Organizations’ Promotion of Cancer Services
Authors: Carson William O. , Little Alyssa , Monetathchi Angela , Erdrich Jennifer , Cordova-Marks Felina M. 
Published: January 2025

Abstract
The burden of cancer remains elevated for American Indians/Alaska Natives (AI/AN) in the United States, particularly in urban communities. Urban Indian Organizations (UIO) are a part of the Indian healthcare system for urban AI/AN populations to receive culturally competent care; therefore, it is important that UIOs convey the importance of cancer preventive and treatment options through their websites. The purpose of this study was to utilize the Indian Health Service (IHS) Office of Urban Indian Health Programs’ official website to identify, analyze, and describe the IHS-funded UIOs offering cancer-related services. We utilized qualitative content analysis on UIOs with primary care service capabilities. After determination of UIOs, each eligible website was reviewed to determine whether promotion of specific cancer-related services was being done based on the following categories: primary prevention, cancer screening, cancer support, and information/technology services that focus on the social determinants of health. There is limited, vague, or outdated information on UIO websites regarding the type of cancer-related services and programs provided. We found that whereas 21 of 34 UIOs list any mention of cancer screenings, few mentioned specific testing capabilities for various cancers. In addition, the listing of support and preventative services was also limited, with less than half of UIOs reporting on patient navigation services, among others. There is untapped potential in the utilization of websites for extending the impact of UIOs and their work with urban AI/AN populations in prevention, screening, and support of patients with cancer in a culturally appropriate manner that can improve outcomes.

Significance:
To the best of the knowledge of the authors, this is the first study to explore and measure cancer support services through public-facing channels. This study provides important data on how primary care facilities are engaging in public health promotion services in an online setting.