工程技术最新文献

We have previously verified the capabilities of a prototype magnetic nanoparticle (MNP) heater (called HYPER) that can perform spatially confined heating; however, the design lacked temperature control capabilities. In this work, we designed, verified, and validated a relay-based autotuning proportional-integral-derivative (PID) controller to be used with the HYPER during in vivo experiments. The PID controller is an autotuning, relay-based controller with several design constraints: The controller must: (1) maintain tumor temperature within hyperthermic range of 41-46 °C; (2) rise time ≤ 5 min; (3) steady-state temperature must be within ±0.5 °C of the setpoint; (4) standard deviation of steady-state temperature within ±0.5 °C; and (5) temperature overshoot within 5%. The relay-based autotuning PID controller was designed in LabVIEW^® with real-time thermal dose monitoring. Verification experiments were performed by heating aqueous suspensions of high-performance iron oxide MNPs. For validation, we injected the MNPs into tumor-bearing mice and analyzed the ability of the controller to maintain in vivo temperature. The results of the study show that controller was able to maintain the temperature within the hyperthermic range with a rise time ∼4 min and steady-state error ∼0.1 °C. Validation was performed on six mice, where four mice showed the temperature was maintained within design criteria and two mice partially met the design criteria. The autotuning controller can maintain the temperature within the design criteria and monitor thermal dose in real-time.

The colon is a major component of the digestive system, so early detection of colorectal polyps is essential in preventing colorectal cancer, which is a leading cause of cancer-related death worldwide. While colonoscopy remains the gold standard for polyp detection, its diagnostic accuracy is highly operator-dependent. Recent advances in Deep Learning (DL), a branch of Artificial Intelligence (AI), have shown substantial potential to improve colonoscopy image analysis by enhancing the accuracy, consistency, and objectivity of polyp detection, segmentation, and classification. Artificial intelligence-based systems have significantly reduced inter-observer variability and increased diagnostic efficiency, ultimately transforming the landscape of colorectal lesion assessment. This survey provides a comprehensive and critical analysis of the current status of deep learning applications in colorectal polyp analysis. We systematically review state-of-the-art methodologies across various DL architectures-including Convolutional Neural Networks (CNNs), transformer-based models, and hybrid approaches-and examine their performance on publicly available benchmark datasets. Additionally, we highlight the strengths and limitations of existing techniques, explore the clinical relevance of AI-assisted tools, and identify prevailing challenges such as data imbalance, real-time deployment, and generalizability across diverse populations and colonoscopy devices. By consolidating key advances and outlining future research directions, this review aims to serve as a valuable resource for researchers, clinicians, and developers seeking to leverage deep learning to enhance colorectal polyp detection, diagnosis, and clinical decision-making.

Dual X-ray absorptiometry (DEXA) scans are the current standard in assessing bone mineral density (BMD) and are used to identify patients who may need screw augmentation during spinal fusion. DEXA scans are not always available and tend to overestimate BMD. This paper describes the development of a dual-cantilever mechanical probe and tested in polyurethane foam blocks with varying compressive strengths. The probe was modeled after a 5.5 mm tap and foam block holes were prepared replicating intra-operative conditions. Calibration curves were acquired for each probe using six foam blocks (1.5-12.9 MPa). Verification tests were performed in a different set of four foam blocks (2.05-9.65 MPa). Four probes were machined and tested for repeatability. Three users separately acquired measurements of foam blocks to test for reliability. The root-mean-square error of all four probes measuring the 2.05 MPa, 3.65 MPa, 5.80 MPa, and 9.65 MPa samples were 0.89 MPa, 0.32 MPa, 1.41 MPa, and 1.71 MPa, respectively. There was not a significant difference between different probes or different users. The dual-cantilever probe provided measurements within the clinically relevant range of compressive strengths for vertebral trabecular bone. A targeted and reliable bone strength measurement technique could reduce the occurrence and revision surgeries and improve patient outcomes.

Erythromycin, a broad-spectrum antibiotic, is a prototypical polyketide produced via heterologous biosynthesis in Escherichia coli. However, the instability of plasmid‑encoded genes within the erythromycin biosynthetic pathway, coupled with limited intracellular availability of sugar units and propionyl‑CoA, constitutes major bottlenecks that hinder its efficient production in E. coli. In this study, we constructed a de novo erythromycin A producing E. coli strain throughchromosomal integrationand achieved substantial production improvement by enhancing the supply of sugar units for the erythromycin post-modification and propionyl-CoA. To enable precise and efficient transfer of multiple large DNA fragments from different plasmids into the chromosome, we devised achromosomal integrationstrategy employing a reusable target site toolkit, allowing the integration of four gene expression cassettes (total length ∼ 56.2 kb) into the genome of E. coli BAP1, thereby generating the recombinant strain E. coli sZG9. Subsequently, the availability of sugar units was increased by systematically blocking competing metabolic pathways and introducing a Ser45Asn mutation in the negative regulatory site of phosphoglucomutase, which elevated erythromycin A production from 1.06 mg/L to 5.53 mg/L. Finally, a Lys592Asn mutation in the negative regulatory site of propionyl-CoA synthetase further boosted the production to 9.80 mg/L, representing an 8.25-fold increase over the parental strain. This work establishes an effective large-fragment DNA chromosomal integrationapproach and provides a promising chassis strain for future metabolic engineering efforts aimed at enhancing erythromycin A biosynthesis in E. coli.

Follicular thyroid carcinoma (FTC) is the second most common thyroid cancer. Preoperative differentiation between benign and malignant follicular tumors remains challenging using ultrasound and fine needle aspiration biopsy (FNAB). Radiomics quantitatively evaluates diseases by extracting and analyzing features from medical images. This study aimed to assess the diagnostic value of ultrasound radiomics in distinguishing follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA) among TI-RADS 4a nodules. A retrospective analysis was conducted on the ultrasound images from 144 patients with TI-RADS 4a follicular thyroid neoplasms who underwent their first surgery in our hospital from January 2018 to June 2024. First, ultrasonographic characteristics (US) were analyzed from ultrasound images and diagnostic reports to build a US model. Second, ultrasound radiomics features were extracted from ultrasound images by the software of 3D-Slicer. According to the postoperative pathological results, the patients were divided into FTC group and FTA group. Following the principle of random allocation, the ratio of the training group (n = 86) to the validation group (n = 58) was 6:4. The ultrasound radiomics features were selected by the Least Absolute Shrinkage and Selection Operator (LASSO) algorithm in order to build a radiomics model. Finally, a combined model integrating ultrasonographic characteristics and radiomics features (combined-model) was developed. All models including US model, radiomics model and combined-model were built through multi-factor logistic regression analysis to differentiate and diagnose follicular thyroid neoplasms. The receiver operating characteristic curve (ROC), precision, recall and F1-Score were used to evaluate the efficacy of the models. One hundred forty-four patients with TI-RADS 4a follicular thyroid neoplasms were divided into FTC group (41 cases) and FTA group (103 cases) based on postoperative pathological results. A total of 858 ultrasound radiomics features were extracted from the ultrasound images. After screening, six optimal radiomics features were obtained. Among the three models, the combined-model demonstrated best performance in differentiating FTC from FTA, with the area under the curve (AUC) of 0.839 (95% CI: 0.663-1.000) in the validation group. The F1-Score reflected a balance between precision and recall, with overall performance being superior. Combined model of ultrasonographic characteristics and radiomics may be useful to distinguish FTC from FTA.

Tracheal and distal airway imaging enhance the evaluation of mucociliary clearance (MCC) and respiratory health. Herein, we characterize in vivo pulmonary imaging performance of a microbubble (MB) contrast agent optimized for muco-adhesion. A three-way crossover trial (12 mice, 3 imaging timepoints each) was conducted to evaluate tracheal ultrasound image enhancement following oropharyngeal instillation of standard MBs, our optimized MB formulation (TAP-cationic MBs), and lipid solution control. The feasibility of delivering our TAP-cationic MBs as an aerosol to the distal airways was also evaluated using a porcine model. Contrast imaging procedures were well-tolerated by both animal models. In mice, tracheal delineation was comparably enhanced with TAP-cationic MBs (contrast-to-noise ratio [CNR]: 42.26 dB) and standard MBs (CNR: 45.09 dB). Both exceeded lipid solution control (CNR: 11.9 dB, p < .05). In the porcine model, nebulized administration of TAP-cationic MBs yielded MB accumulation in the distal airways visible on transcutaneous ultrasound. Modifying the standard MB formulation to optimize muco-adhesion does not diminish image enhancement when administered oropharyngeally as a liquid solution, and when administered as an aerosol, TAP-cationic MBs deposit, and can be visualized in the distal lung airways. These findings support further development of MB contrast agents for pulmonary applications.

Microbial protein is a resource-efficient alternative to conventional protein, and gas-fed systems based on methane- and hydrogen-oxidizing bacteria are attractive because they directly convert gaseous C1 substrates into biomass, without reliance on arable land or organic feedstocks. We examined whether co-cultivating these organisms improves carbon retention by enabling in situ reuse of CO₂ released during CH₄ oxidation. After selecting a compatible pair (Methylomonas koyamae and Cupriavidus necator), a continuous airlift reactor was operated in four phases with progressively reduced external CO₂ supply. Biomass in the co-culture reached 2.1 ± 0.5 g L^-1, with protein contents of 50-65% (dry weight). Off-gas CO₂ decreased to near zero, corresponding to a marked increase in carbon-use efficiency from 47% to 91%. Amino acid composition and digestibility, expressed as the Digestible Indispensable Amino Acid Score, remained stable across phases, and sensory evaluation indicated a lighter colour and cleaner aroma for the co-culture biomass. This study demonstrates a continuous methane- and hydrogen-oxidizing bacteria process achieving near-complete CO₂ recycling and high-quality microbial protein production.

To develop dynamic monitoring and quantitative analysis of voluntary skeletal muscle contractions. A novel micro wearable ultrasound system was evaluated in 40 healthy female participants. Using pulsed wave Doppler imaging, we captured the muscle bundle contraction of the flexor digitorum superficialis in dominant hands during repeated isotonic contractions for 8 seconds, in a cycle of five rounds. Waveform patterns and derived peak systolic velocity (PSV) and muscle systolic time (MST) were recorded and analyzed. Participants with low skeletal muscle mass index (SMI < 5.7 kg/m²) or first-quartile handgrip strength (HS) exhibited a split waveform with bidirectional systolic patterns and reduced PSV stability (PSV was 10.24-11.31 cm/s and 10.12-11.71 cm/s for subjects with low-SMI or low-HS in the first round, and was 9.04-11.29 cm/s and 9.86-10.72 cm/s in the last round). In contrast, subjects with higher muscle mass and strength had regular muscle contraction waveforms and higher PSV, which decreased with increasing grip counts and recovered after rest (PSV was 11.11-15.47 cm/s and 11.21-14.88 cm/s for subjects with normal-SMI or normal-HS in the first round, and was 10.63-13.94 cm/s and 10.09-13.97 cm/s in the last round). The micro wearable ultrasound device enables continuous imaging of voluntary skeletal muscle contraction, and the waveforms and their derived quantitative indicators vary among individuals with different muscle mass and strength.