[Negative Poisson's Ratio Material Structure Based on 3D Printing and Its Application in Medical Field].

First of all, the overall framework of 3D printing is briefly introduced, including the basic principles of the additive manufacturing process, the classification and summary of the seven processes. Secondly, the common negative Poisson's ratio structure is introduced. Compared with the conventional structure, the negative Poisson's ratio structure has stronger energy absorption capacity, better fracture resistance and better indentation resistance, which are its advantages in printing manufacturing. Finally, 3D printing, the application of negative Poisson's ratio structure and the combination of the two are introduced from the different perspective of medical field, for example, the application of cardiovascular stent, biomedical material structure preparation, and lumbar disc implants. This paper suggests that the structural design of negative Poisson's ratio in 3D printing guides the development of new application directions in the medical field. Negative Poisson's ratio materials have a wide range of applications, not only in the medical field but also in mechanical equipment, automotive manufacturing, aerospace, and other high-tech industries.

Clinical significance of platelet mononuclear cell aggregates in patients with sepsis and acute respiratory distress syndrome.

BACKGROUND: The diagnosis of sepsis combined with acute respiratory distress syndrome (ARDS) has increased owing to the enhanced awareness among medical professionals and the continuous development of modern medical technologies, while early diagnosis of ARDS still lacks specific biomarkers. One of the main pathogenic mechanisms of sepsis-associated ARDS involves the actions of various pathological injuries and inflammatory factors, such as platelet and white blood cells activation, leading to an increase of surface adhesion molecules. These adhesion molecules further form platelet-white blood cell aggregates, including platelet-mononuclear cell aggregates (PMAs). PMAs has been identified as one of the markers of platelet activation, here we hypothesize that PMAs might play a potential biomarker for the early diagnosis of this complication. AIM: To investigate the expression of PMAs in the serum of patients with sepsis complicated by ARDS and its clinical significance. METHODS: We selected 72 hospitalized patients diagnosed with sepsis as the study population between March 2019 and March 2022. Among them, 30 patients with sepsis and ARDS formed the study group, while 42 sepsis patients without ARDS comprised the control group. After diagnosis, venous blood samples were immediately collected from all patients. Flow cytometry was employed to analyze the expression of PMAs, platelet neutrophil aggregates (PNAs), and platelet aggregates (PLyAs) in the serum. Additionally, the Acute Physiology and Chronic Health Evaluation (APACHE) II score was calculated for each patient, and receiver operating characteristic curves were generated to assess diagnostic value. RESULTS: The study found that the levels of PNAs and PLyAs in the serum of the study group were higher than those in the control group, but the difference was not statistically significant (P > 0.05). However, the expression of PMAs in the serum of the study group was significantly upregulated (P < 0.05) and positively correlated with the APACHE II score (r = 0.671, P < 0.05). When using PMAs as a diagnostic indicator, the area under the curve value was 0.957, indicating a high diagnostic value (P < 0.05). Furthermore, the optimal cutoff value was 8.418%, with a diagnostic sensitivity of 0.819 and specificity of 0.947. CONCLUSION: In summary, the serum levels of PMAs significantly increase in patients with sepsis and ARDS. Therefore, serum PMAs have the potential to become a new biomarker for clinically diagnosing sepsis complicated by ARDS.