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关键词： C4 photosynthesis   CO2 concentrating mechanism   Crassulacean acid metabolism   Ottelia alismoides   PEP carboxylase   photosynthesis   Rubisco   single-cell  

摘要： Many plants maximize photosynthesis by using a CO2-concentrating mechanism (CCM). Based on physiology, the freshwater plant Ottelia alismoides has three CCMs: C4 metabolism (NAD-malic enzyme (NAD-ME) subtype) and bicarbonate-use during the day plus crassulacean acid metabolism (CAM) at night and lacks Kranz anatomy. Here, we combined a range of techniques including analysis of enzyme activity and location, transcriptomics, proteomics and 13C labelling in plants grown at low and high concentrations of CO2 to investigate how these CCMs interact and can be integrated without Kranz anatomy. We showed that, unlike canonical NAD-ME subtypes, malate is the first stable compound, produced by a cytosolic malate dehydrogenase, rather than aspartate produced by aspartate aminotransferase. CAM depends on the nocturnal synthesis and transport of malic acid into the vacuole involving a vacuolar-ATPase and a tonoplast dicarboxylate transporter that are highly expressed at night. These results show that C4 and CAM are compatible within a single cell, thanks to temporal regulation and expression of different isoforms of key enzymes and transporters. They contribute to the growing appreciation of the diversity of CCMs and how different processes can co-occur and be coordinated. This study presents a model that could facilitate future plant engineering.

关键词： LDCT image denoising   Cascade attention mechanism   DWT   ECGB   MAB   CAM  

摘要： Low-dose computed tomography (LDCT) has become the core technology in clinical diagnosis, but quantum noise introduced by reducing radiation dose seriously affects image quality and diagnostic accuracy. To solve this problem, we propose WHformer, an LDCT denoising network based on multi-scale feature fusion in the wavelet domain and cascaded attention mechanism. Firstly, the input image is decomposed into high-frequency and low-frequency components by using discrete wavelet transform (DWT), and the multi-scale feature components are aligned by transposition convolution operation as the input of the network. Secondly, an enhanced convolutional gating block (ECGB) and multi-scale attention block (MAB) are proposed, and their cascades are used as the core components of codecs to achieve the cooperative expression of local and global features by combining deep separable convolution and multi-scale attention mechanisms. In addition, a cross-dimensional attention module (CAM) is introduced between codecs. This module not only enhances the capability of cross-level feature fusion but also overcomes the limitation of traditional attention mechanisms that focus solely on a single dimension. The experimental results of the algorithm in this paper on the AAPM Challenge dataset show that, compared with the suboptimal model, PSNR and SSIM have increased by 1.51% and 3.19% respectively, RMSE has decreased by 8.05%, and the best effect has also been achieved on the Piglet dataset. These results fully verify that WHformer model proposed by us can not only effectively suppress the noise in LDCT images, but also retain more image details and significantly improve LDCT image quality.

关键词： coronary CT angiography   CAD-RADS 2.0   large language models  

摘要： Objective: To assess whether few-shot prompting improves the performance of 2 popular large language models (LLMs) (ChatGPT o1 and DeepSeek-R1) in assigning Coronary Artery Disease Reporting and Data System (CAD-RADS (TM) 2.0) categories Methods: A detailed few-shot prompt based on CAD-RADS (TM) 2.0 framework was developed using 20 reports from the MIMIC-IV database. Subsequently, 100 modified reports from the same database were categorized using zero-shot and few-shot prompts through the models' user interface. Model accuracy was evaluated by comparing assignments to a reference radiologist's classifications, including stenosis categories and modifiers. To assess reproducibility, 50 reports were reclassified using the same few-shot prompt. McNemar tests and Cohen kappa were used for statistical analysis. Results: Using zero-shot prompting, accuracy was low for both models (ChatGPT: 14%, DeepSeek: 8%), with correct assignments occurring almost exclusively in CAD-RADS 0 cases. Hallucinations occurred frequently (ChatGPT: 19%, DeepSeek: 54%). Few-shot prompting significantly improved accuracy to 98% for ChatGPT and 93% for DeepSeek (both P<0.001) and eliminated hallucinations. Kappa values for agreement between model-generated and radiologist-assigned classifications were 0.979 (0.950, 1.000) (P<0.001) for ChatGPT and 0.916 (0.859, 0.973) (P<0.001) for DeepSeek, indicating almost perfect agreement for both models without a significant difference between the models (P=0.180). Reproducibility analysis yielded kappa values of 0.957 (0.900, 1.000) (P<0.001) for ChatGPT and 0.873 [0.779, 0.967] (P<0.001) for DeepSeek, indicating almost perfect and strong agreement between repeated assignments, respectively, with no significant difference between the models (P=0.125). Conclusion: Few-shot prompting substantially enhances LLMs' accuracy in assigning CAD-RADS (TM) 2.0 categories, suggesting potential for clinical application and facilitating system adoption.

关键词： Biomaterial science   Retention and stability  

摘要： Objective: This study examined the biomechanical properties of computer-aided design/computer-aided manufacturing (CAD/CAM) retainers made of titanium and nickel-titanium (NiTi). Methods: Four retainer types were tested: (1) twisted steel, (2) NiTi, (3) cut titanium, and (4) printed titanium. Longitudinal wires were manufactured (2-4) and subjected to a three-point bending test (3PBT). In a biomechanical bending test (BMT), retainers were designed from patient scans and applied to models in an Orthodontic Measurement and Simulation System, with the maxillary central incisor and mandibular central incisor loaded with deflections of +/- 0.2 mm and rotation of +/- 1 degrees. Results: The 3PBT showed that NiTi wires exhibited a characteristic hysteresis loop, whereas the cut and printed titanium wires had different flow and yield strengths. The BMT forces during intrusive and extrusive movements were measured, and the findings revealed that in the maxilla, all CAD/CAM materials showed significant differences from the twisted steel, with NiTi differing from the cut and printed titanium. In the mandible, the forces were generally higher, with significant differences observed at 0.1-mm extrusion and 0.2-mm deflection. In addition, significant differences were observed in the mesial and distal deflections, particularly in the mandible, where the cut titanium generated the lowest forces. Twisted steel exhibited the lowest torque, whereas cut titanium exhibited the highest torque. Conclusions: CAD/CAM retainers differ significantly from conventional twisted steel retainers, with notable differences between NiTi and titanium retainers, especially in the maxilla. However, these differences may be negligible in the mandible due to the shorter interdental distance.

关键词： femoroacetabular impingement syndrome   total hip replacement   outcome   register   risk factor  

摘要： Purpose Patients with femoroacetabular impingement syndrome (FAIS) may experience persistent hip problems following arthroscopic surgery, with some patients requiring total hip arthroplasty (THA). Therefore, the purpose was (1) to investigate the proportion of THA conversion in a large national Danish cohort of patients with FAIS who had previously undergone hip arthroscopy. (2) To investigate factors that might affect time to conversion. (3) To describe patient-reported outcomes after THA. Methods Patients aged 18 years or above registered with arthroscopic surgery for FAIS between January 2012 and November 2023 in the Danish Hip Arthroscopy Registry (DHAR). Eligible patients were invited to participate in an online survey. If they responded 'yes' to the entry question 'Have you had total hip arthroplasty?', they were asked to complete the Copenhagen Hip and Groin Outcome Score (HAGOS), the Hip Osteoarthritis Outcome Score (0-100 scores, 100 being no problems), the Hip Specific Sports Scale, and Patient Acceptable Symptom State. To perform survival analysis, a Kaplan-Meier method was used to estimate cumulative all-cause conversion to THA. A Cox regression model was fitted after examining proportional-hazards assumptions to examine predictor variables on conversion to THA. Results A total of 5109 patients were eligible and invited for the survey. Of which, 2383 (46.6%) responded;406 patients had received THA at a median of 4.2 [2.1;7.0] years after hip arthroscopy. Regarding HAGOS, patients (N = 199) treated with THA reported mild pain (75 [55;93] points) and problems with daily activities (70 [40;90] points) and moderate problems with sports activities (53 [28;81] points) and hip-related quality of life (50 [30;80] points), 56% participated in sports activities and 62% reported an acceptable symptom state. Conclusions A low number of conversions to THA (8%) was observed. Older age decreased lateral joint space width, T & ouml;nnis grade > 0, higher alpha angle and

关键词： Cams   Nonvolatile memory   Magnetic tunneling   Switches   Sensors   Numerical models   Error analysis   Voltage   Topology   Resistance   Content-addressable memory   ternary CAM   CAM   precharge-free   MRAM   MTJ   DMTJ  

摘要： Content-addressable memories (CAMs) are a class of associative memories known for their capability to perform massively parallel comparisons between an input query pattern and the entire memory content. In the past decade, the increasing demand for high-performance and energy-efficient computing systems has generated significant interest in non-volatile CAMs (NV-CAMs) based on emerging non-volatile memory devices. In this work, we propose a novel non-volatile, precharge-free CAM (NV-PCAM) scheme based on double-barrier magnetic tunnel junctions (DMTJs). When compared to its counterparts, NV-PCAM presents competitive figures of merit in terms of area, speed, and energy efficiency, while also ensuring low search error rates. We also provide a complete class of voltage-divider-based NV-CAM cells for benchmark comparison. All schemes are designed and laid out using a 65 nm process and evaluated under Monte Carlo and process-voltage-temperature (PVT) simulations. Through Monte Carlo simulations, the proposed NV-PCAM demonstrates up to 81% and 85% lower search energy than NV-NOR and NV-NAND, respectively, as well as a 61% and 16% improvement in terms of search delay with a compact cell area footprint.

关键词： LM2I   ASS1   liver cancer   pyrimidine synthesis  

摘要： The urea cycle occurs mainly in the liver and undergoes changes during hepatocarcinogenesis. Argininosuccinate synthase 1 (ASS1) is a key enzyme in the urea cycle and is expressed at low levels in certain cancers. LM2I, a specific activator of ASS1, exhibits significant antitumor activity. However, the antitumor mechanism of LM2I in liver cancer remains unclear. In this study, we find that LM2I is more effective for liver cancer cells with low ASS1 expression. The results of the IP-LC/MS experiments reveal that ASS1 interacts with CAD. The expressions of ASS1 and CAD in liver cancer tissues and cells are negatively correlated. LM2I promotes the ubiquitination of CAD protein through ASS1. LM2I inhibits the proliferation of liver cancer cells in vivo and in vitro. However, its efficacy is weak in liver cancer cells stably overexpressing CAD. The H&E staining results reveal that LM2I has no toxicity in mice. In terms of metabolism, LM2I increases the urea content and decreases the pyrimidine content in liver cancer cells. Overexpression of CAD can reduce the inhibitory effect of LM2I on pyrimidine. Pyrimidine supplementation facilitates the proliferation of liver cancer cells, particularly when they are treated with LM2I. In summary, ASS1 interacts with CAD, and LM2I enhances CAD degradation through the activation of ASS1, consequently inhibiting pyrimidine

摘要： This digital clinical report presents a novel CAD-CAM workflow for fabricating a customized monolithic zirconia post-and-core restoration. A 26-year-old female patient required prosthetic rehabilitation of the maxillary left first and second premolars, as well as an implant screw-retained crown (ISRC) for the maxillary left first molar. After post space preparation, intraoral scans (IOS) were obtained both with and without a prefabricated fiber post in place. The fiber post was also scanned separately using a desktop scanner. These datasets were superimposed using digital software to design a precise monolithic zirconia post-and-core, which was then milled using CAD-CAM technology. The structure was cemented with self-adhesive resin cement, and a lithium disilicate crown was digitally designed and fabricated. This digital approach minimized the errors associated with conventional techniques, improved fit and adaptation, and enhanced clinical efficiency. The definitive restoration achieved excellent aesthetic and functional outcomes, fulfilling the patient's expectations without complications. This report highlights the value of digital workflows in achieving precision and predictability in post-and-core restorations.

摘要： Hip morphology has emerged as an important factor in the development of hip osteoarthritis (OA). Cam morphology is one of the most common hip morphologies, characterized by a bony prominence around the femoral head-neck junction of the hip that alters the normal shape of the femoral head. Cam morphology can contribute to intra-articular joint damage by generating abnormal contact stresses at this junction, initiating femoroacetabular impingement (FAI) syndrome and eventually leading to hip OA. Cam morphology is a causal risk factor for hip OA, but not everybody with this morphology will develop FAI syndrome or OA. The pathogenesis of hip disease is probably driven by the interplay between cam morphology, other coexisting hip morphologies (such as pincer morphology), femoral version, spinopelvic parameters and biomechanical and environmental factors. Early identification of FAI syndrome could enable timely, multidisciplinary intervention and offers the potential to modify the trajectory of disease. Cam morphology can develop during skeletal maturation, particularly in adolescents participating in high-joint-load physical activity, raising important questions about preventative approaches. Management of FAI syndrome includes both surgical and non-surgical approaches. Emerging insights into the pathogenesis and detection of cam morphology are paving the way for more targeted interventions and a deeper understanding of its role in FAI syndrome and hip OA development.