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Finite element simulation is one of the effective means to study the stress evolution of thermally grown oxides （TGO） at the interface of thermal barrier coatings （TBCs）， which can provide theoretical support for exploring the failure mechanism of TBCs. Advanced thermal barrier coating multifactor coupling test equipment was used to conduct thermal-mechanical coupling cycle tests and thermal cycling tests on circular tube specimens coated with TBCs， simulating engine operating conditions. Finite element modeling was conducted on TBCs containing real initial TGO morphology using finite element software ABAQUS， and the stress and deformation patterns of the coatings during tests were analyzed. The results show that without considering TGO and interface cracking， both the thermal-mechanical coupling model and the thermal cycle model exhibit an increase in Mises stress as the number of cycles increases. During the heating process， TGO is subjected to tension， while during the cooling process， TGO is compressed. The stress during the heating process is much lower than that during cooling to room temperature. After the same number of cycles， the stress values in thermal-mechanical coupling model are higher than those in the thermal cycle model. After 20， 45， 70 thermal cycles， the TGO stresses at room temperature reach 2.85， 3.65 GPa and 3.55 GPa， respectively. After the same number of thermal-mechanical coupling cycles；when cooling to room temperature，TGO stresses at the same position at room temperature reach 4.01 GPa， 5.0 GPa and 4.81 GPa， respectively. Compared with thermal cycles， under thermal coupling conditions， the TGO stress significantly increased after the same cycles when cooling to room temperature.

Partially stabilized zirconia （7YSZ） with a mass fraction of 7±1% yttrium oxide is a widely used ceramic material for thermal barrier coatings. However， its phase stability， sintering resistance， and mechanical properties decreased during the long-time operation above 1200 ℃. A new type of Sc2O3-Y2O3 co-doped ZrO2 thermal barrier coating ceramic material was proposed ， and a molar fraction of 7.5%Sc2O3-x%Y2O3-（92.5-x）%ZrO2（x=0，0.1，0.2，0.3） ceramics were prepared by solid-state reaction method. The effects of Y2O3 doping on the microstructural， phase evolution， and mechanical properties（including Vickers hardness， fracture toughness， elastic modulus and three-point bending strength）were explored by XRD， SEM， and other testing methods. The results show that the relative density of Sc2O3-Y2O3 doped ZrO2 ceramics sintered at 1450 °C for 3.5 h is more than 97%， and the phase structure is composed of tetragonal phase. Compared with 6-8YSZ ceramics， Sc2O3-Y2O3 doped ZrO2 ceramics exhibit similar Vickers hardness （13-14 GPa）， fracture toughness （6.5-7.0 MPa·m1/2）， elastic modulus （211-214 GPa）and three-point bending strength（520-850 MPa）. Fracture mechanism shows a mixture of transgranular and intergranular fracture modes， in which transgranular fracture is dominant.This ceramic can be explored as a potential thermal barrier coating material for high-temperature applications.

Precise measurement of the thermal insulation performance of thermal barrier coatings (TBCs) under the thermal gradient environment is important for the design and development of TBCs. A phosphorescent sensor TBC which contains an Eu doped yttria-stabilized zirconia (YSZ:Eu) surface layer, a YSZ intermediate layer, and a YSZ:Dy bottom layer, is designed and prepared by electron beam physical vapor deposition (EB-PVD). Based on the thermal quenching characteristics of phosphorescence signal, the surface temperature of the YSZ coating and the interface temperature of the bond-coat/YSZ layer are measured online in a temperature gradient environment, and the real thermal insulation effect of the EB-PVD YSZ thermal barrier coating is evaluated. The results show that the EB-PVD YSZ coating with a thickness of 113 μm can achieve an average temperature decrease of 66.5 ℃. The average thermal conductivity of the coating is (0.87±0.15) W/(m·K) in the temperature range between 400 and 700 ℃, which is slightly lower than the value (0.95±0.02) W/(m·K) obtained by using the traditional laser flash method. The above results validate the reliability of online phosphorescence temperature measurement technique, and provide an effective method to monitor the thermal insulation effect of TBCs in real time.

In order to study the oxidation corrosion protection of key components of carrier aero engine, the high temperature oxidation behavior of the Ni-based powder metallurgy(PM) superalloys FGH4095 and FGH4096 in air at the temperature range of 750-1100 ℃ was investigated. The oxidation kinetics curves were determined by static weighing method. The structure, composition, and morphology of the surface oxide scale as well as its cross section were analyzed by metallographic microscope, scanning electron microscope (SEM), electron probe microanalyzer (EPMA) and X-ray diffractometer (XRD). The results show that two kinds of alloys belong to the grade of full oxidation resistance at 750-900 ℃ and oxidation resistance at 1000-1100 ℃. The actual service temperature of both alloys is below 900 ℃, so they exhibit excellent oxidation resistance in their operating temperature range.At 750-900 ℃, the oxidation resistance of the two alloys is similar without obvious difference. The oxide film is intact without peeling.The oxide films of FGH4095 and FGH4096 are composed of two layers after high temperature oxidation. The internal layer is mainly Al2O3.The outer layer of FGH4095 is composed of Cr2O3, Nb2O5 and TiO2. The outer layer of FGH4096 is composed of only Cr2O3 and TiO2.At 1100 ℃, both alloys are obviously oxidized and a large number of oxide scales crack. Due to the different compositions of the alloys, the oxidation resistance of the two alloys varies greatly at this temperature.In contrast, FGH4095 alloy exhibits better oxidation resistance.

Objective The prognosis of patients with brain metastases is poor and lacking in unifieddiagnosis and treatment standards. The demand for multidisciplinary team(MDT) diagnosis and treatment mode is extremely high. This study retrospectively summarizes the data of patients treated with MDT for brain metastases in order to provide clinical reference. Methods All patients undergoing MDT treatment for brain metastases at the Neurological Tumor Center of Peking Union Medical College Hospital from January 2019 to December 2021 were retrospectively included. The clinical characteristics, diagnosis and treatment decisions, treatment compliance, clinical prognosis, etc. at the time of enrollment were summarized, and the influencing factors of patients' prognosis were analyzed. Results A total of 159 patients who underwent MDT for brain metastases were included(13 cases with non-cerebral metastases). The most common source of tumor was lung cancer(61.6%), followed by breast cancer(11.3%). The vast majority of patients(87.4%) received only 1 MDT visit. The main characteristics of patients at the time of the initial MDT consultation for brain metastases were primary diagnosis of brain metastases(90.6%), good general condition(Karnofsky functional status score ≥70, 79.2%), age ≤65 years(78.6%), pathological findings of primary site or intracranial metastases(67.9%), tumor origin of lung cancer(61.6%), and single intracranial lesion(54.1%). 76.7%(122/159) of the patients reaching specific treatment recommendations after MDT diagnosis and treatment, 9.4%(15/159) of the patients having changes in diagnosis, and 56.6%(90/159) of the patients exercising full compliance with MDT diagnosis and treatment recommendations at the time of 1-year follow-up. The 6-month survival rate of the 146 patients with brain metastases was 85.6%(125/146) and the 1-year survival rate was 78.8%(115/146). Kaplan-Meier survival curve showed that recursive partition analysis grading and grading prognosis evaluation score had guiding significance for prognosis stratification of patients with brain metastases. Multivariate Cox regression analysis showed that women(HR=0.437, 95% CI: 0.231-0.828) and patients with brain metastases who fully complied with MDT diagnosis and treatment recommendations(HR=0.498, 95% CI: 0.264-0.942) generally had a better prognosis. Conclusions It is necessary to set reasonable conditions for patients with brain metastases to be enrolled in order to improve the diagnosis and treatment efficiency of MDT. Most patients with brain metastases reached specific treatment recommendations after MDT diagnosis and treatment, and the patients had good treatment compliance. The diagnosis and treatment of MDT may help improve the overall survival rate of patients, but the exact benefits need to be evaluated individually.

Improving machinability has consistently been an essential research topic in the machining community. However, a rapid and effective method to characterize machinability from the fundamental essence of machining is still lacking. This work proposed a new characterization methodology for assessing machinability from the principle of cutting energy consumption. An original Drop Hammer based Orthogonal Cutting (DHOC) test machine driven by gravitational potential energy was developed to conduct the machinability test. Using the Cutting Distance with Equal Energy (CDEE) method, machinability can be assessed by measuring the cutting distance without expensive measuring apparatus. Therefore, the cutting distance indicator can simplify the test procedure. Meanwhile, the CDEE method avoids the necessity for precisely calculating the consumptions of various complex cutting energies. Moreover, in-situ measurements coupled with the Digital Image Correlation (DIC) technique and Electron Back-Scattered Diffraction (EBSD) characterizations were utilized to evaluate the deformation characteristics and surface integrity during the CDEE tests. The proposed CDEE method has been validated from three aspects involving materials, cutting tools, and surface modification technology. Furthermore, a machinability optimization procedure based on the CDEE method has been proposed. The cutting distance indicator was used as an optimization objective for optimizing technology parameters to improve machinability. This CDEE method based on the DHOC test machine proved to have high application potential for the characterization and optimization of machinability. [ABSTRACT FROM AUTHOR]

Cell-to-cell mitochondrial transfer has recently been shown to play a role in maintaining physiological functions of cell. We previously illustrated that mitochondrial transfer within osteocyte dendritic network regulates bone tissue homeostasis. However, the mechanism of triggering this process has not been explored. Here, we showed that stressed osteocytes in mice release adenosine diphosphate (ADP), resulting in triggering mitochondrial transfer from healthy osteocytes to restore the oxygen consumption rate (OCR) and to alleviate reactive oxygen species accumulation. Furthermore, we identified that P2Y2 and P2Y6 transduced the ADP signal to regulate osteocyte mitochondrial transfer. We showed that mitochondrial metabolism is impaired in aged osteocytes, and there were more extracellular nucleotides release into the matrix in aged cortical bone due to compromised membrane integrity. Conditioned medium from aged osteocytes triggered mitochondrial transfer between osteocytes to enhance the energy metabolism. Together, using osteocyte as an example, this study showed new insights into how extracellular ADP triggers healthy cells to rescue energy metabolism crisis in stressed cells via mitochondrial transfer in tissue homeostasis. Cell-to-cell mitochondrial transfer within the osteocyte dendritic network regulates bone tissue homeostasis, but the underlying mechanisms remain unknown. This study show that osteocytes release ADP under stress conditions, triggering mitochondrial transfer to achieve tissue homeostasis. [ABSTRACT FROM AUTHOR]

Background: The diagnosis of glioma has advanced since the release of the WHO 2021 classification with more molecular alterations involved in the integrated diagnostic pathways. Our study aimed to present our experience with the clinical features and management of astrocytoma, IDH mutant based on the latest WHO classification. Methods: Patients diagnosed with astrocytoma, IDH‐mutant based on the WHO 5th edition classification of CNS tumors at our center from January 2009 to January 2022 were included. Patients were divided into WHO 2–3 grade group and WHO 4 grade group. Integrate diagnoses were retrospectively confirmed according to WHO 2016 and 2021 classification. Clinical and MRI characteristics were reviewed, and survival analysis was performed. Results: A total of 60 patients were enrolled. 21.67% (13/60) of all patients changed tumor grade from WHO 4th edition classification to WHO 5th edition. Of these, 21.43% (6/28) of grade II astrocytoma and 58.33% (7/12) of grade III astrocytoma according to WHO 4th edition classification changed to grade 4 according to WHO 5th edition classification. Sex (p = 0.042), recurrent glioma (p = 0.006), and Ki‐67 index (p < 0.001) of pathological examination were statistically different in the WHO grade 2–3 group (n = 27) and WHO grade 4 group (n = 33). CDK6 (p = 0.004), FGFR2 (p = 0.003), and MYC (p = 0.004) alterations showed an enrichment in the WHO grade 4 group. Patients with higher grade showed shorter mOS (mOS = 75.9 m, 53.6 m, 26.4 m for grade 2, 3, and 4, respectively, p = 0.01). Conclusions: Patients diagnosed as WHO grade 4 according to the 5th edition WHO classification based on molecular alterations are more likely to have poorer prognosis. Therefore, treatment should be tailored to their individual needs. Further research is needed for the management of IDH‐mutant astrocytoma is needed in the future. [ABSTRACT FROM AUTHOR]

The failure mechanism of a thermal barrier coatings (TBCs) system is investigated using cyclic thermo-mechanical loading with a thermal gradient. Hollow circular cylindrical specimens are employed, consisting of a nickel-based single-crystal alloy DD6 coated with a NiCoCrAlYHf bond coat via arc-ion plating and a surface electron beam physical vapor deposited (EB-PVD) yttria-stabilized zirconia topcoat. The experimental setup allows for a surface temperature of 1130 °C and a substrate temperature of 1070 °C, while a tensile mechanical load of 200 MPa is employed to simulate the centrifugal stress in the middle of the high-pressure turbine blade. The comparison between TBCs with and without mechanical loading implies that the coupled thermo-mechanical load significantly promotes coating spallation since the superposition of mechanical strain enhances the local tensile stress at the peak region of the topcoat/thermally grown oxides (TGOs) interface. A subsequent interfacial morphology analysis demonstrates that the topcoat/TGO interface exhibited a degradation in the direction parallel to the mechanical loading axis. For all the specimens, TGO comprises a duplex structure, consisting of outer spinel and inner α-Al2O3. [ABSTRACT FROM AUTHOR]

BACKGROUND: No studies have been retrieved comparing perfluorobutane with sulfur hexafluoride for microwave ablation (MWA) in small hepatocellular carcinoma(sHCC). OBJECTIVE: To retrospective investigate the value of perfluorobutane ultrasonography contrast agent in ultrasonography (US)-guided MWA of sHCC. METHODS: We conducted a retrospective clinical controlled study about US-guided percutaneous MWA in patients with sHCC, and in patients undergoing intra-operative treatment with perfluorobutane or sulfur hexafluoride. In both groups, a contrast agent was injected to clear the tumor and then a needle was inserted. A 5-point needle prick difficulty score was developed to compare needle prick difficulty in the two groups of cases. RESULTS: A total of 67 patients were included: 25 patients in group perfluorobutane, aged 41–82 (60.64±9.46), tumor size 1.1–2.8 (1.78±0.45) cm. 42 patients in group sulfur hexafluoride, aged 38–78 (62.26±9.27), with tumor size of 1.1–3.0 (1.89±0.49) cm. There was no significant difference in age or tumor size in both groups (P > 0.05). Puncture difficulty score (5-point): 2.0–2.7 (2.28±0.29) in group perfluorobutane, and 2.0–4.7 (2.95±0.85) in group sulfur hexafluoride, and the difference between the two groups was statistically significant (P < 0.05). Enhanced imaging results within 3 months after surgery: complete ablation rate was 100% (25/25) in the group perfluorobutane, 95.2% (40/42 in the group sulfur hexafluoride), with no significant difference between the two groups (P > 0.05). CONCLUSION: Perfluorobutane kupffer phase can make the operator accurately deploy the ablation needle and reduce the difficulty of operation. [ABSTRACT FROM AUTHOR]

The management of urban flood disasters is a systematic engineering project that requires a great amount of manpower, material resources, and financial resources, and the interaction and coordination degrees of various elements in the system deeply affect the efficiency of the final governance. According to the theories of synergy, composite systems, and sustainable development, this research first established an evaluation index system to determine the synergy degree of urban flood disaster emergency management from the four dimensions of prevention and preparation, monitoring and early warning, response and rescue, and recovery and reconstruction. Then, the synergy degree was explored by using the developed composite system synergy degree model on the basis of the panel data of 18 prefecture-level cities in Henan Province from 2013 to 2021, and synergy level change characteristics were analyzed from the perspectives of time and space. Finally, the obstacle degree model was applied to explore the obstacle factors affecting synergy degree development. The results showed that the overall level of the urban flood disaster emergency management coordination degree in Henan Province was relatively low, and there were significant differences in synergy among cities. Among them, 12 cities presented mild synergy, and 6 cities showed mild nonsynergy. The spatial correlation of the synergy degree was not stable, which revealed a lack of mature coordination mechanisms for flood disaster emergency management among cities. The analysis of obstacle factors showed that recovery and reconstruction subsystems were the main obstacle systems that affected the synergy degree. [ABSTRACT FROM AUTHOR]