In order to control the forming surface quality of signal crystal turbine blade tenon teeth in the creep feed grinding, the influence of the creep feed grinding parameters on the grinding surface ...integrity of DD5 nickel-based single crystal superalloy was investigated via orthogonal experiment. The results showed that the surface roughness along vertical grinding direction was ranged at 0.56-0.74 μm at the grinding wheel speed range of 15-30 m/s, feeding velocity range of 120-210 mm/min and grinding depth range of 0.1-0.7 mm, and the surface roughness in the grinding direction is about 1/5 of that in the vertical grinding direction. The surface topography and texture results showed that there were the obvious grooves and ridges on the grinding surface caused by the grain ploughing and scratching, the length and height of grooves and ridges on the grinding surface changed obviously under different processing parameters, and the three-dimensional topography of the grinding surface fluctuated obviously. The length of grooves and ridges along the grinding direction were sensitive to the speed of grinding wheel, waviness of grooves and ridges along the vertical grinding direction were sensitive to the grinding depth and workpiece feed rate. The different degrees of work hardening effect were presented at the grinding surface, the biggest work hardening effect achieved at 11.6%, and the maximum depth of work hardening effect was 110 μm. The distinct plastic deformation appeared at the grinding surface. The
γ
phase presented slip deformation along the grinding direction with various degrees, and the
γ
'
phase presented skewing, twisting, broken and fracture, the maximum depth of plastic deformation was 2.92 μm. The work hardening effect of DD5 creep feed grinding mainly due to the plastic deformation degree at the grinding surface. The experimental conclusions provided theoretical guidance for DD5 signal crystal turbine blade tenon teeth.
为控制单晶涡轮叶片榫齿缓进磨削成形表面质量, 通过实验研究缓进磨削工艺参数对DD5镍基单晶高温合金磨削表面完整性的影响规律。实验结果表明, 当砂轮线速度在15~30 m/s、工件进给速度在120~210 mm/min、磨削深度在0.1~0.7 mm参数范围内, 磨削表面垂直磨削方向粗糙度在0.56~0.74 μm范围内, 沿磨削方向粗糙度约为垂直磨削方向粗糙度的1/5。三维形貌和表面纹理测试结果表明磨削表面存在明显的因磨粒耕犁和划擦而产生的表面凹槽和材料隆起现象, 不同工艺参数下磨削表面凹槽和隆起材料的长度和高度有较明显变化; 砂轮线速度对沿磨削方向凹槽和隆起长度影响较敏感; 磨削深度和工件进给速度对垂直磨削方向的凹槽和隆起轮廓起伏程度敏感。磨削表面出现了不同程度加工硬化, 最高达11.6%, 最大硬化层深度达到110 μm; 磨削表面层出现明显塑性变形,
γ
相沿着磨削方向出现不同程度的滑移变形, 立方化的
γ
'
相出现了偏移、扭曲、破碎断裂现象, 最大塑性变形层厚度为2.92 μm; DD5缓进磨削塑性变形是加工硬化产生主要原因。实验结果对DD5榫齿磨削提供理论指导。
Few models about the personalized prognosis evaluation of buccal mucosa cancer (BMC) patients were reported. We aimed to establish predictive models to forecast the prognosis of BMC patients.
The ...complete clinicopathological information of BMC patients from the surveillance, epidemiology and end results program was collected and reviewed retrospectively. Two nomograms were established and validated to predict long-term overall survival (OS) and cancer-specific survival (CSS) of BMC patients based on multivariate Cox regression survival analysis.
1155 patients were included. 693 and 462 patients were distributed into modeling and validation groups with 6:4 split-ratio via a random split-sample method. Based on the survival analysis, independent prognostic risk factors (variables that can be used to estimate disease recovery and relapse chance) influencing OS and CSS were obtained to establish nomograms. Then, we divided the modeling group into high- and low-risk cohorts. The low-risk cohort had improved OS and CSS compared to the high-risk cohort, which was statistically significant after the Log-rank test (p < 0.05). Furthermore, we used the concordance index (C-index), calibration curve to validate the nomograms, showing high accuracy. The decision curve analyses (DCA) revealed that the nomograms had evident clinical value.
We constructed two credible nomogram models, which would give the surgeons reference to provide an individualized assessment of BMC patients.
Cranioplasty with freehand-molded polymethylmethacrylate implants is based on decades of experience and is still frequently used in clinical practice. However, data confirming the fracture toughness ...and standard biomechanical tests are rare. This study aimed to determine the amount of force that could be applied to virtually planned, template-molded, patient-specific implants (n = 10) with an implant thickness of 3 mm, used in the treatment of a temporoparietal skull defect (91.87 cm2), until the implant cracks and finally breaks. Furthermore, the influence of the weight and porosity of the implant on its force resistance was investigated. The primary outcome showed that a high force was required to break the implant (mean and standard deviation 1484.6 ± 167.7 N), and this was very strongly correlated with implant weight (Pearson’s correlation coefficient 0.97; p < 0.001). Secondary outcomes were force application at the implant’s first, second, and third crack. Only a moderate correlation could be found between fracture force and the volume of porosities (Pearson’s correlation coefficient 0.59; p = 0.073). The present study demonstrates that an implant thickness of 3 mm for a temporoparietal skull defect can withstand sufficient force to protect the brain. Greater implant weight and, thus, higher material content increases thickness, resulting in more resistance. Porosities that occur during the described workflow do not seem to reduce resistance. Therefore, precise knowledge of the fracture force of polymethylmethacrylate cranial implants provides insight into brain injury prevention and serves as a reference for the virtual design process.
The differentiated pricing strategy of charging operators can guide the charging behaviour of electric vehicle (EV) users, which can not only make the charging operators obtain maximum profit but ...also make the EV charging service more efficient, thereby promoting the development of the EV industry. This study builds an evolutionary game model between EV users and charging operators in Shanghai, explores the interaction process between the two, simulates the evolutionary stable equilibrium and conducts the sensitivity analysis of the main factors affecting the equilibrium. The results show that there are two possible equilibrium states in this evolutionary game system: (1) choosing private charging piles and providing slow charging piles; (2) choosing shared charging piles and providing fast charging piles. The evolution of the game system is mainly affected by the prices of slow shared, fast shared and private charging piles. The price of the private charging pile significantly affects the strategy choice of EV users. In regions where the price of a private charging pile is low, charging operators can lower the prices of slow shared charging and fast shared charging piles, guiding more EV users to choose shared charging piles.
•An evolutionary game model for EV users and charging operators is established.•Theoretical analysis is conducted for gaming of EV users and charging operator.•Simulation analysis is conducted to find the evolutionary equilibrium stable points.•The Private pile charging price affects the decision of charging operators.•Charging price can guide the charging behaviour of EV users.
19F magnetic resonance imaging (19F MRI) is gaining attention as an emerging diagnostic technology. Effective 19F MRI contrast agents (CAs) for in vivo applications require a long transverse (or ...spin-spin) relaxation time (T2), short longitudinal (or spin-lattice) relaxation time (T1), high fluorine content, and excellent biocompatibility. Here, we present a novel hyperbranched polymeric 19F MRI CA based on β-cyclodextrin and phosphorylcholine. The influence of the branching degree and fluorine content on T2 was thoroughly investigated. Results demonstrated a maximum fluorine content of 11.85% and a T2 of 612 ms. This hyperbranched polymeric 19F MRI CA exhibited both great biocompatibility against cells and organs of mice and high-performance imaging capabilities both in vitro and in vivo. The research provides positive insights into the synthesis strategies, topological design, and selection of fluorine tags for 19F MRI CAs.19F magnetic resonance imaging (19F MRI) is gaining attention as an emerging diagnostic technology. Effective 19F MRI contrast agents (CAs) for in vivo applications require a long transverse (or spin-spin) relaxation time (T2), short longitudinal (or spin-lattice) relaxation time (T1), high fluorine content, and excellent biocompatibility. Here, we present a novel hyperbranched polymeric 19F MRI CA based on β-cyclodextrin and phosphorylcholine. The influence of the branching degree and fluorine content on T2 was thoroughly investigated. Results demonstrated a maximum fluorine content of 11.85% and a T2 of 612 ms. This hyperbranched polymeric 19F MRI CA exhibited both great biocompatibility against cells and organs of mice and high-performance imaging capabilities both in vitro and in vivo. The research provides positive insights into the synthesis strategies, topological design, and selection of fluorine tags for 19F MRI CAs.
The repair of large bone defects poses a significant challenge in orthopedics. Polyetheretherketone (PEEK) is a promising bone substitute, while it suffers a lack of bioactivity. Although several ...studies have been performed to further improve the bioactivities of PEEK by various surface modifications, PEEK offering long-term, multifaceted biofunctionalities remains still desired. In this study, we introduced metal-organic frameworks (MOFs), specifically ZIF-8 loaded with celecoxib (ZIF-8(CEL)), onto the PEEK surface through dopamine adhesion. The resulting PEEK@ZIF-8(CEL) aims to achieve long-term stable release of Zn ions and CEL for enhanced bone integration. Material characterization and biological experiments confirmed the successful integration of ZIF-8(CEL) onto PEEK and its positive biomedical effects, including creating a positive bone immunological environment and promoting bone growth. This study demonstrates the potential of PEEK@ZIF-8(CEL) as a novel repair material for large bone defects, offering a promising alternative in orthopedic applications.The repair of large bone defects poses a significant challenge in orthopedics. Polyetheretherketone (PEEK) is a promising bone substitute, while it suffers a lack of bioactivity. Although several studies have been performed to further improve the bioactivities of PEEK by various surface modifications, PEEK offering long-term, multifaceted biofunctionalities remains still desired. In this study, we introduced metal-organic frameworks (MOFs), specifically ZIF-8 loaded with celecoxib (ZIF-8(CEL)), onto the PEEK surface through dopamine adhesion. The resulting PEEK@ZIF-8(CEL) aims to achieve long-term stable release of Zn ions and CEL for enhanced bone integration. Material characterization and biological experiments confirmed the successful integration of ZIF-8(CEL) onto PEEK and its positive biomedical effects, including creating a positive bone immunological environment and promoting bone growth. This study demonstrates the potential of PEEK@ZIF-8(CEL) as a novel repair material for large bone defects, offering a promising alternative in orthopedic applications.
In response to the escalating challenge of bacterial drug resistance, the imperative to counteract planktonic cell proliferation and eliminate entrenched biofilms underscores the necessity for ...cationic polymeric antibacterials. However, limited efficacy and cytotoxicity challenge their practical use. Here, novel imidazolium‐based main‐chain copolymers with imidazolium (PIm+) as the cationic component are introduced. By adjusting precursor molecules, hydrophobicity and cationic density of each unit are fine‐tuned, resulting in broad‐spectrum bactericidal activity against clinically relevant pathogens. PIm+1 stands out for its potent antibacterial performance, with a minimum inhibitory concentration of 32 µg mL−1 against Methicillin‐resistant Staphylococcus aureus (MRSA), and substantial biofilm reduction in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) biofilms. The bactericidal mechanism involves disrupting the outer and cytoplasmic membranes, depolarizing the cytoplasmic membrane, and triggering intracellular reactive oxygen species (ROS) generation. Collectively, this study postulates the potential of imidazolium‐based main‐chain copolymers, systematically tailored in their sequences, to serve as a promising candidate in combatting drug‐resistant bacterial infections.
Collectively, this study postulates the potential of imidazolium‐based main‐chain copolymers, systematically tailored in their sequences, to serve as a promising candidate in combatting drug‐resistant bacterial infections.
Large defects of jaw caused by tumor, trauma and so on in oral and maxillofacial region lead to facial deformity, language and chewing dysfunction, which severely damage the patient's life quality. ...Three-dimensional printing (3DP) is also named additive manufacturing (AM), which can print materials layer by layer to create three-dimensional objects. The complex shape of jaw defects can be accurately reconstructed using 3DP scaffold combined with image data, computer-aided-design and manufacture. It has specific advantages compared with traditional way of jaw reconstruction and has attracted much attention in the field of jaw tissue engineering recently. This article presented the progress of 3DP scaffold and its application in jaw reconstruction, providing a new idea for jaw reconstruction.
It is a challenge to effectively reactivate preexisting tumor-infiltrating lymphocytes (TILs) without causing severe toxicity. Interleukin-12 (IL-12) can potently activate lymphocytes, but its ...clinical use is limited by its short half-life and dose-related toxicity. In this study, we developed a tumor-conditional IL-12 (pro-IL-12), which masked IL-12 with selective extracellular receptor–binding domains of the IL-12 receptor while preferentially and persistently activating TILs after being unmasked by matrix metalloproteinases expressed by tumors. Systemic delivery of pro-IL-12 demonstrated reduced toxicity but better control of established tumors compared with IL-12-Fc. Mechanistically, antitumor responses induced by pro-IL-12 were dependent on TILs and IFNγ. Furthermore, direct binding of IL-12 to IL-12R on CD8
, not CD4
, T cells was essential for maximal effectiveness. Pro-IL-12 improved the efficacy of both immune checkpoint blockade and targeted therapy when used in combination. Therefore, our study demonstrated that pro-IL-12 could rejuvenate TILs, which then combined with current treatment modalities while limiting adverse effects for treating established tumors.
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