Science Progress最新文献

ObjectiveTo establish a predictive model based on ultrasound (US) radiomics to determine whether the ablation zone of papillary thyroid microcarcinoma (PTMC) disappears within 24 months after microwave ablation (MWA).Study designRetrospective study.MethodsThis study enrolled 201 PTMC patients who underwent MWA in Affiliated Beijing Friendship Hospital of Capital Medical University between January 2013 and September 2020. All patients were followed up at 1 h, 1 month, 3 months, 6 months, 12 months, and 24 months after MWA. Radiomics features were extracted from the preoperative US images, and a Rad-score was constructed. Univariate and multivariate logistic regression analyses were used to screen out the independent clinical factors associated with the disappearance of the ablation zone after MWA, and a radiomics nomogram was established to predict whether the ablation zone of PTMC disappeared within 24 months after MWA. The performance of the model was validated in the testing cohort.Results75.6% of patients achieved the ablation zone disappeared within 24 months after MWA. The disappearance rate was significantly associated with MWA energy and baseline lesion volume (p < 0.05). The US radiomics nomogram integrated Rad-score, MWA energy, and baseline lesion volume. In the testing cohort, the area under the curve of this nomogram outperformed that of the clinical model and the radiomics model (0.772 vs 0.714 and 0.679, respectively).ConclusionsThe nomogram based on US radiomics can reliably identify whether lesions of PTMC will disappear within 24 months after MWA. The nomogram is useful for screening optimal candidates for MWA and may assist clinicians and patients in choosing the best treatment option between MWA and surgery.

Wellbore instability in deep hard-brittle shale formations, primarily induced by hydration-driven strength degradation upon interaction with water-based fluids, poses a critical challenge to hydrocarbon extraction. Conventional triaxial testing for assessing shale hydration behavior is often constrained by substantial sample requirements, extended duration, and high operational costs. In response, this study develops an efficient alternative approach centered on the indentation hardness method. While standard indentation tests are typically limited to hardness and plasticity coefficients, this work establishes theoretical models-based on contact mechanics, elasticity theory, and the Mohr-Coulomb criterion-to derive elastic modulus, Poisson's ratio, and uniaxial compressive strength from indentation data. Experimental analysis of homogenized Longmaxi shale revealed a dense, low-porosity microstructure dominated by non-expansive clay minerals and quartz. Freshwater immersion tests displayed a three-stage absorption trend-rapid, slow, and stable-reaching near-saturation after 72 hours. Pronounced mechanical degradation was observed within the initial 300 hours of immersion, characterized by marked reductions in compressive strength, elastic modulus, and indentation hardness, alongside a stepwise increase in Poisson's ratio; this degradation trend decelerated thereafter. Validation experiments confirmed that single-point indentation hardness measurements provide mechanical equivalence to uniaxial compression responses. As a result, indentation testing on shale chips following fluid immersion offers an efficient and reliable means of evaluating time-dependent fluid-rock interactions. The proposed methodology minimizes core material requirements, enhances operational efficiency, and mitigates the influence of heterogeneity, thereby offering considerable practical value for shale hydration assessment and wellbore stability forecasting.

ObjectiveQuantify recruitment of Native Hawaiian and Pacific Islander (NHPI) participants from 22 Alzheimer's disease (AD) clinical trials over 5 years and utilize choropleth maps as a visual tool to identify where in the Hawaiian community recruited participants are located in order to better inform future recruitment efforts and improve equity and population diversity for future AD clinical trials.MethodsA retrospective chart review was conducted at a dual-site origin clinical trial center in Hawai'i. Inclusion criteria were a diagnosis of mild cognitive impairment and participation in one or more AD clinical trials conducted between 2020 and 2024. Demographic information of clinical trial participants was collected via chart review and included self-identified race/ethnicity, age, residence, and number of clinical trials the patient has participated in. Clinical trial participants were categorized by ZIP codes established by the US Census Bureau. Differences across race/ethnicity groups were assessed using either Pearson's Chi-squared test or Fisher's exact test.ResultsA total of 244 patients participated across the state of Hawai'i in 22 AD clinical trials between 2020 and 2024. Of this total, 169 (69%) patients provided their race/ethnicity, and 75 (31%) did not provide their race/ethnicity. White patients had the highest percentage of participation (44%), followed by Asian patients (34%) and NHPI patients (15%). The population distribution visualized in this study's choropleth maps suggests that NHPI were under-recruited from the west side of O'ahu.ConclusionsOur retrospective study applied choropleth maps to visualize the recruitment data and patterns of AD clinical trials. By utilizing choropleth maps to analyze recruitment areas, the NHPI community and other underrepresented populations may benefit from targeted, culturally informed recruitment strategies.

ObjectiveTraditional indicators of obesity, such as body mass index (BMI), fail to precisely capture the independent impact of fat distribution on gallstone disease (GSD). This study aimed to investigate the nonlinear association between body fat ratio (BFR) and the risk of GSD and to identify a critical threshold value.MethodWe conducted a cross-sectional observational analysis of 1952 adults from the 2017-2018 National Health and Nutrition Examination Survey (NHANES). BFR was measured by dual-energy X-ray absorptiometry, and GSD was defined by standardized questionnaire data. Weighted logistic regression, restricted cubic spline (RCS), and threshold effect models were employed to examine the association between BFR and GSD risk, as well as to determine the inflection point.ResultsA significant J-shaped nonlinear association was observed between BFR and GSD risk (P for non-linearity < 0.001). Threshold analysis identified 29.1% (95% CI: 27.5-30.7%) as the critical inflection point, beyond which each 1% increase in BFR was associated with a 14% higher odds of GSD (OR = 1.14, 95% CI: 1.09-1.19). After multivariate adjustment, each additional 1% increase in BFR remained independently associated with a 7% increased risk (OR = 1.07, 95% CI: 1.02-1.13). Compared with participants in the lowest quartile, those in the highest quartile (BFR≥39.2%) exhibited a 2.66-fold higher risk of GSD. Subgroup analyses demonstrated stronger associations in males (OR ≈ 1.12 per 1% BFR increase) and Hispanics (OR ≈ 1.20 per 1% BFR increase).ConclusionsBFR of ≥29.1% represents a critical threshold beyond which GSD risk significantly increases. These findings suggest an association that warrants further investigation into whether routine monitoring of BFR could serve as a valuable screening tool in high-risk populations, and precise intervention strategies should consider gender and ethnic differences to effectively mitigate metabolic-related gallstone disease.

To address the limitations of flux regulation in traditional permanent magnet synchronous generators and the low power density of electrically excited generators, an interior double-radial asymmetric permanent magnet (PM) and salient-pole electromagnetic hybrid excitation generator are introduced in this study. Equations for the no-load induced electromotive force, the voltage adjustment range, and the total harmonic distortion (THD) are derived theoretically through the analysis of generator parameter relationships. The optimization parameters include the offset angles of the double-layer asymmetric PMs and the structural parameters of the salient-pole rotor. A multi-objective optimization model is established with the no-load induced electromotive force amplitude, the voltage adjustment range, and the THD as the objectives. Samples are generated by Latin Hypercube Sampling, followed by sensitivity analysis of the optimization parameters. The optimization parameters are then screened using Pareto front analysis and a defined parameter matching coefficient. The optimal magnet pole parameters are determined. As a result of optimization, the no-load induced electromotive force amplitude increases by 18.7%, the voltage adjustment range expands by 17.6%, and the THD decreases by 38.2%. Finally, a prototype is fabricated and tested, and the results confirm both the accuracy of the theoretical analysis and the effectiveness of the optimization method. The output characteristics of the designed generator are thereby significantly improved.

ObjectivesAlthough bone marrow mesenchymal stromal cells (BMSCs) are extensively used in biomedicine, they have yet to be used in the commercial development of a tissue engineered medicine. It has been argued that the major roadblock in their commercial deployment is the lengthy in vitro culture periods required for the development of implantable tissue surrogates. Macromolecular crowding (MMC) has been shown to enhance and increase extracellular matrix deposition in eukaryotic cell culture, allowing for the accelerated development of tissue facsimiles.MethodsWith these in mind, human BMSCs were cultured under MMC conditions and the developed tissue-engineered medicine was assessed in vitro and in vivo in a humanised athymic nude mouse excisional wound splinting model.ResultsStarting with basic cell function analysis, MMC did not significantly affect cell metabolic activity, viability and proliferation. Electrophoresis and immunofluorescence analyses revealed that MMC significantly increased collagen type I and collagen type IV deposition, without significantly affecting collagen type III deposition. Flow cytometry analysis demonstrated similar CD44, CD73, CD90, CD146, HLA-ABC, CD31, CD45, CD80 and CD86 expression between the without and the with MMC groups. Interestingly though the MMC group had higher CD105 and lower HLA-DR expression than the without MMC group. Preclinical analysis revealed similar wound closure, scar index and epidermal thickness between the without and the with MMC groups, largely attributed to issues encountered with the model.ConclusionsOverall, this preliminary study demonstrates the potential of MMC in the accelerated development of functional and extracellular matrix-rich human BMSC-based tissue-engineered medicines.

ObjectiveTo validate a serial multimodal ultrasound (MMUS) protocol for assessing dynamic tibialis anterior changes in detecting intensive care unit-acquired weakness (ICUAW) and to develop a diagnostic algorithm.MethodsIn a prospective cohort of 97 high-risk adults (mean age 60.7±13.7 years; 73.2% male; SOFA score ≥8 for ≥3 days), MMUS quantified structural (thickness, echogenicity), hemodynamic (perfusion grade, peak systolic velocity [PSV]), and mechanical (elastic modulus) parameters of the tibialis anterior at ICU admission (Day 1) and Day 7. ICUAW was diagnosed per American Thoracic Society guidelines. Serum biomarkers (IL-6, PCT, CRP) were correlated with sonographic changes. Diagnostic models were constructed using binary logistic regression and evaluated by ROC analysis.Results31 patients (32.0%) developed ICUAW. By Day 7, the ICUAW group showed greater structural deterioration (echogenicity progression: 54.8% vs. 16.7%, P < 0.001), hemodynamic changes (PSV: 7.60 ± 1.72 vs. 6.35 ± 1.78 cm/s, P < 0.001), and faster stiffness increase (elastic modulus rate: 14.1±12.3% vs. 5.4±6.0%, P < 0.001). Day 7 PSV correlated with IL-6 (r = 0.59), PCT (r = 0.50), and CRP (r = 0.68) (all P < 0.05). A 7-parameter model achieved an AUC of 0.917 (95%CI: 0.857-0.978) with an NPV of 92.4%.ConclusionDynamic MMUS captures ICUAW pathophysiology. The proposed algorithm shows potential as a non-invasive bedside tool for early risk stratification, pending multicenter validation.

To reveal the mechanical response and energy conversion mechanism of deep gas-bearing layered coal under impact loads, coal samples from a gas outburst mine in Gansu Province were taken as the research object. Based on a three-dimensional combined dynamic-static load testing system, impact tests were conducted on coal samples with different bedding angles β (0°, 30°, 45°, 60°, and 90°) under a gas pressure of 0.8 MPa. A preset axial static load of 2 MPa and confining pressure of 4 MPa were applied, followed by loading with an impact pressure of 0.6 MPa. The stress-strain curves, mechanical parameters, failure modes, and energy evolution laws were analyzed. The results show that the peak strength presents a U-shaped distribution with the change of bedding angle: it reaches the highest values at 0° (160.41 MPa) and 90° (164.66 MPa), and the lowest at 45° (124.96 MPa). This is because the shear stress concentration effect on the bedding plane is the strongest at 45°, making it easy for cracks to propagate along the bedding. The peak strain also shows a U-shaped trend, reaching 0.03 at 90°and stabilizing at 0.026 at 30°and 45°, which reflects the differences in the deformation mechanisms of coal samples under different angles. In terms of energy evolution, the total energy density (U) and dissipated energy density (U_d) are higher and grow faster at 0°and 90°, while the elastic energy density (U_e) shows obvious post-peak release only at 0°. In the range of 30°∼60°, the values of U and U_d are low, and the release of U_e is weak, which is consistent with the low energy consumption characteristics of shear failure along the bedding. The failure mode changes regularly with the bedding angle: multi-directional fragmentation at 0°, shear fragmentation along the bedding mainly at 30°∼45° (the most severe fragmentation at 45°), and cross-bedding splitting failure at 90°. The study confirms that bedding angle regulates the mechanical properties and energy distribution of coal by changing the stress distribution and crack propagation path. The research results can provide key quantitative parameter support for the assessment and prevention of dynamic disasters in deep gas-bearing coal.

ObjectiveSepsis remains a primary contributor to mortality among critically ill individuals, and the assessment of vascular stiffness, indicated by estimated pulse wave velocity (ePWV), could offer insights into patient outcomes. This retrospective cohort study examines the correlation between ePWV levels and all-cause mortality in individuals with sepsis.MethodsA total of 22,166 sepsis patients from the MIMIC-IV database were included. Cox regression analysis, restricted cubic spline (RCS) analysis, and subgroup analyses were conducted to evaluate the association between ePWV and 30-day and 365-day mortality.ResultsThe 30-day and 365-day mortality rates were 18.28% and 32.93%, respectively. Compared to the first quartile (Q1), patients in the highest ePWV quartile (Q4) had a 92% higher risk of 30-day mortality (HR: 1.92, 95% CI: 1.73-2.13, p < 0.001) and an 75% higher risk of 365-day mortality (HR: 1.75, 95% CI: 1.62-1.89, p < 0.001) in adjusted models. RCS analysis identified a nonlinear association between ePWV and mortality (p for non-linearity < 0.001) with inflection points at 9.04 m/s for 30-day mortality and 10.81 m/s for 365-day mortality. The nomogram model demonstrated good performance in predicting both 30-day and 365-day mortality, with area under the curve values of 0.736 and 0.775 in the training set, respectively.ConclusionsThis study demonstrates that higher ePWV is significantly associated with increased short- and long-term mortality risk in critically ill sepsis patients, with evidence of a nonlinear relationship. ePWV may serve as a valuable prognostic marker to identify sepsis patients at higher risk of mortality in the ICU.