工程技术最新文献

Ultrasound elastography is a novel technology that assesses tissue elasticity. Elastography has been studied in subpleural consolidations, yet findings remain contradictory. This study aims to evaluate the utility of 2D-SWE for differentiating benign and malignant consolidations and to develop a simplified protocol accessible to inexperienced operators and applicable to all patients, regardless of clinical status. Prospective single-center study conducted in a tertiary care hospital. We enrolled 101 consecutive patients with consolidation identified on chest CT or X-ray. 2D-SWE was preferentially performed during forced inspiration; when unfeasible, measurements were acquired during end-expiration or spontaneous breathing. Quantitative measurements (shear wave speed, m/s; and elastic modulus, kPa), alongside qualitative elasticity scores, demonstrated statistically significant differences in distinguishing benign and malignant consolidations during multivariate analysis. ROC curve analysis identified optimal diagnostic cutoffs of 1.72 m/s and 9.1 kPa, both exhibiting 89% sensitivity and 80% specificity. The predominant measurement method was spontaneous breathing (90.1%). 2D-SWE effectively differentiates benign and malignant subpleural consolidations. Our simplified protocol, requiring only five valid measurements and adaptable to spontaneous breathing, if ratified in future studies, could replace complex techniques like prolonged apnea and serve as the standardized method in future clinical guidelines.

Lignin condensation and the recalcitrance of lignocellulose during conventional fractionation limit their valorization. Herein, we develop a tunable ternary deep eutectic solvent (TDES) composed of guanidine hydrochloride, lactic acid, and ethylene glycol for efficient fractionation of moso bamboo. By modulating the EG content, 74.3% delignification was achieved while preserving lignin structure, as confirmed by a β‑O‑4 content of 26.3/100 Ar (61.3% retention). Lignin nanoparticles self‑assembled into uniform lignin nanobottles (LNBs) with size controlled by lignin structure. Moreover, the preserved structural integrity enabled a high bio‑oil yield of 39.7 wt%. 4‑Vinylphenol was identified by Py‑GC/MS as the dominant product. Strong positive correlations were observed between β‑O‑4 content and both LNBs size and bio‑oil yield. Enzymatic saccharification of the treated residue achieved up to 94.4% glucose conversion. This work establishes a clear structure‑property relationship and presents a "structure‑first" strategy for dual‑pathway lignin valorization into nanomaterials and fuels.

Lignin-carbohydrate complex (LCC), natural plant cell wall macromolecules, has garnered increasing attention for multifunctional bioactivities attributed to a unique lignin-polysaccharide hybrid structure. However, conventional separation methods often compromise the structural integrity and biological function of LCC, limiting practical applications. Herein, a novel two-step xylanase-cellulase method was developed to efficiently isolate functional group-enriched LCC (XCE-LCC) with enhanced free radical scavenging and α-glucosidase inhibitory activities. Comparative analyses revealed that the two-step method partially removed cellulose and hemicellulose barriers while preserving the native LCC structure. Notably, XCE-LCC contained increased levels of bioactive functional groups (phenolic-OH: 0.93 mmol/g, -COOH: 0.23 mmol/g, and aliphatic-OH: 4.38 mmol/g) resulting in DPPH radical scavenging (58.7 %) and particularly high α-glucosidase inhibition (87.4 %). These findings demonstrate an effective enzymatic method for functional group-enriched LCC isolation and underscore the potential of LCC as a functional polymer for oxidative stress mitigation and natural α-glucosidase inhibition.

In shear wave elastography, viscoelastic properties of tissues can be estimated by fitting a rheological model to the phase velocity dispersion curve. However, there is a lack of consensus on the model that best represents tissue behavior. Model-free elastography approaches based on shear wave attenuation (SWA) and dispersion slope analysis have been reported previously. This study evaluated the ability of SWA and dispersion slope analysis to assess fluid content in situ using viscoelastic phantoms and ex vivo chicken breast. Model-free parameters were estimated in viscoelastic phantoms (with fluid percentages ranging from 72.6% to 79.9%, and pre- and post-compression by 10%) and ex vivo chicken breast samples pre- and post-hydration. Estimates of SWA were computed using the frequency-shift (FS) and the attenuation measuring shear wave elastography (AMUSE) methods. Dispersion slopes were computed from the phase velocity dispersion curves. The SWA coefficient estimates were strongly correlated with the fluid percentages in phantoms (r = 0.86 and 0.92 for FS and AMUSE methods, respectively, p < 0.001). However, no trends were observed for dispersion slope estimates (r = -0.73, p < 0.001). Thus, SWA was found to be a more sensitive parameter than the dispersion slope for differentiating phantoms with a range of in situ fluid content. Additionally, when phantoms were subjected to compression, SWA was sensitive to changes in compression-induced fluid variations in situ (p < 0.05), but dispersion slope showed no such trends (p = 0.12). The SWA estimates of ex vivo samples significantly increased post-hydration using both methods (p < 0.05), while the dispersion slope decreased. The findings of this study demonstrate that SWA is sensitive to fluid content in situ, which motivates its further development as a marker to assess pathological conditions.

Detecting ovarian structures in ultrasound images is essential in gynecological and reproductive medicine. An automated detection system can serve as a valuable tool for physicians and assist in complex ultrasound interpretations. This study presents a CNN-based object detector designed to segment and count follicle regions in ovarian ultrasound images. Automated identification of ovarian follicles can aid in diagnosing conditions such as infertility, Polycystic Ovarian Syndrome (PCOS), ovarian cancer, and other reproductive health issues. The proposed model, Multi-Attention Residual Dilated UNet with Squeeze and Excitation (MARDSE-UNet), integrates residual UNet, dilated UNet, and squeeze-and-excitation blocks to enhance follicle detection performance. MARDSE-UNet achieved exceptional results, with 98.69% accuracy, 97.89% precision, 97.7% recall, an F1-score of 86.97%, and Intersection over Union (IoU) of 95.66% in follicle detection using 5-fold cross-validation. The USOVA3D dataset was used for experimentation. The model also incorporates a novel preprocessing stage to address noise and low contrast issues, as well as a post-processing stage to refine edges and extract features such as area, perimeter, and diameter of follicles for a more comprehensive performance comparison. The proposed model outperformed traditional CNN models and other state-of-the-art methods in comparative evaluations.

Toluene o-xylene monooxygenase (ToMO) of Pseudomonas sp. OX1 was investigated as a drug-metabolizing enzyme for the first time and was found to metabolize chlorzoxazone and resveratrol to form human metabolites 6-chlorzoxazone (0.045 ± 0.016 nmol/hr/mg protein) and piceatannol (0.014 ± 0.009 nmol/hr/mg protein), respectively, though at low rates. ToMO also forms 2-acetamidophenol (2-AAP, 27%), 3-AAP (42%), and 4-AAP (31%) from acetanilide at 3.6 ± 0.3 nmol/hr/mg protein. Multiple-site saturation mutagenesis at positions I100/E103/A107 of the alpha-subunit along with site-directed mutagenesis approaches were used to isolate thirty-seven different ToMO variants with enhanced activities and/or fine-tuned specificities. Specifically, variant I100V/E103T was identified with 2.1- and 49-fold higher activities towards acetanilide and chlorzoxazone, respectively, compared to native ToMO. Variant I100V/E103T also had the regiospecificity of acetanilide change from 31% to 100% 4-AAP, mimicking human liver enzyme behavior. In addition, several variants showed up to 3.7-, 1.6-, and 3.2-fold improved selectivity for 2-, 3-, and 4-AAP formation, respectively. For resveratrol, variant I100T/E103L was a better catalyst than native ToMO, exhibiting 34-fold higher activity. The results presented here demonstrate the potential of nonhuman ToMO variants in drug metabolism and contribute to the list of research on probing this promising enzyme.