Majorana Corner Modes and Flat-Band Majorana Edge Modes in Superconductor/Topological-Insulator/Superconductor Junctions

Recently,superconductors with higher-order topology have stimulated extensive attention and research interest.Higher-order topological superconductors exhibit unconventional bulk-boundary correspondence,thus allow exotic lower-dimensional boundary modes,such as Majorana corner and hinge modes.However,higher-order topological superconductivity has yet to be found in naturally occurring materials.We investigate higher-order topology in a two-dimensional Josephson junction comprised of two s-wave superconductors separated by a topological insulator thin film.We find that zero-energy Majorana corner modes,a boundary fingerprint of higherorder topological superconductivity,can be achieved by applying magnetic field.When an in-plane Zeeman field is applied to the system,two corner modes appear in the superconducting junction.Furthermore,we also discover a two-dimensional nodal superconducting phase which supports flat-band Majorana edge modes connecting the bulk nodes.Importantly,we demonstrate that zero-energy Majorana corner modes are stable when increasing the thickness of topological insulator thin film.

Creep aging behavior of retrogression and re-aged 7150 aluminum alloy

Creep aging behavior of retrogression and re-aged(RRAed)7150 aluminum alloy(AA7150)was systematically investigated using the creep aging experiments,mechanical properties tests,electrical conductivity tests and transmission electron microscope(TEM)observations.Creep aging results show that the steady-state creep mechanism of RRAed alloys is mainly dislocation climb(stress exponent≈5.8),which is insensitive to the grain interior and boundary precipitates.However,the total creep deformation increases over the re-aging time.In addition,the yield strength and tensile strength of the four RRAed samples are essentially the same after creep aging at 140℃ for 16 h,but the elongation decreases slightly with the re-aging time.What’s more,the retrogression and re-aging treatment are beneficial to increase the hardness and electrical conductivity of the creep-aged 7150 aluminum alloy.It can be concluded that the retrogression and re-aging treatment before creep aging forming process can improve the microstructure within grain and at grain boundary,forming efficiency and comprehensive performance of mechanical properties and electrical conductivity of 7150 aluminum alloy.

First-in-man implantation of the retrievable and repositionable VenusA-Plus valve

BACKGROUND: No retrievable and repositionable second generation transcatheter aortic valve is available in China. Here, we report the first-in-man implantation of the retrievable and repositionable VenusA-Plus valve. METHODS: A 76-year-old patient with symptomatic severe aortic stenosis and high surgical risk(STS 13.8%) was recommended for transcatheter aortic valve replacement(TAVR) by heart valve team. Type 0 bicuspid aortic valve with asymmetric calcification was identified by dual source computed tomography, and the unfavorable anatomies increased the possibility of malposition and paravalvular leakage during TAVR. Therefore, we used the retrievable and repositionable Venus APlus valve for the patient.RESULTS: Transfemoral TAVR was performed under local anesthesia with sedation, and a 26-mm VenusA-Plus valve was successfully implanted. No transvalvular pressure gradient and trace paravalvular leakage were found. CONCLUSION: The successful first-in-man implantation indicates the retrievable and repositionable Venus A-Plus valve is feasible in complicated TAVR cases such as bicuspid aortic valve.

Anemia and risk of periprocedural cerebral injury detected by diffusion-weighted magnetic resonance imaging in patients undergoing transcatheter aortic valve replacement

BACKGROUND: Anemia is prevalent in patients undergoing transcatheter aortic valve replacement(TAVR) and has been linked to impaired outcomes after the procedure. Few studies have evaluated the impact of anemia and new ischemic lesions post TAVR.METHODS: We prospectively enrolled 158 patients who received TAVR in our center. Anemia was defined according to the World Health Organization criteria as hemoglobin <12 g/dL in women and <13 g/dL in men. All patients underwent diffusion-weighted magnetic resonance imaging(DW-MRI) procedure before and within 4–7 days after TAVR. RESULTS: Anemia was present in 85(53.8%) patients who underwent TAVR, and 126(79.7%) patients had 718 new DW-MRI positive lesions with a mean of 4.54±5.26 lesions per patient. The incidence of new ischemic lesions was 81.2% in patients with anemia versus 78.1% in patients without anemia(P=0.629). Moreover, anemic patients had bigger total volume/lesions in the anterior cerebral artery/middle cerebral artery(ACA/MCA) and MCA regions compared to the non-anemic patients(31.89±55.78 mm^(3) vs. 17.08±37.39 mm^(3), P=0.049;and 54.54±74.72 mm^(3) vs. 33.75±46.03 mm^(3), P=0.034). Anemia was independently associated with the volume/lesion in the ACA/MCA(β=16.796, 95% confidence interval [95% CI] 2.001 to 31.591, P=0.026) and in the MCA zone(β=0.020, 95% CI 0.001 to 0.040, P=0.041). CONCLUSIONS: Patients with pre-procedural anemia may have bigger total volume/lesions in the ACA/MCA and MCA regions compared to the non-anemic patients. Whether the consequences of bigger total volume/lesions impact neurological and cognitive outcomes remains to be investigated.

Expression and clinical significance of FoxM1 and ADAM17 proteins in colon cancer

Objective:To detect the expression levels of Forkhead box M1 (FoxM1) and Adisintegrin and metalloproteinase (ADAM17) proteins in colon cancer tissues and to analyze their relationship with clinical pathology of colon cancer.And to explore its clinical significance. Methods: From June 2016 to December 2017, 68 cases of colon cancer specimens and normal tissues adjacent to the colon cancer were obtained from the Department of General Surgery, North China University of Technology, and the pathologically confirmed colon cancer specimens were examined by immunohistochemistry. The positive expression rates of FoxM1 and ADAM17 proteins in the two groups were detected by immunohistochemistry, and the relationship between them and the clinicopathological features of colon cancer and their correlation were analyzed.Results: Compared with normal colon tissue, the positive rates of FoxM1 and ADAM17 protein expression in colon cancer tissues were significantly increased (P<0.05). The positive expression rate of FoxM1 and ADAM17 protein was correlated with tumor diameter, lymphatic metastasis and clinical stage (P<0.05), and had no correlation with age, gender, tumor differentiation degree and tumor invasion depth (P>0.05). The results of rank correlation analysis showed that there was a positive correlation between the expression of FoxM1 and ADAM17 protein in colon cancer tissues (rs=0.520,P<0.05).Conclusion: The positive expression rate of FoxM1 and ADAM17 protein in colon cancer tissues was higher than that in normal colon tissues. The positive expression of FoxM1 and ADAM17 was related to colon cancer diameter, lymphatic metastasis and clinical stage, suggesting that it may be related to poor prognosis of colon cancer.

Effect of medial meniscus extrusion on arthroscopic surgery outcome in the osteoarthritic knee associated with medial meniscus tear:a minimum 4-year follow-up

Background:The potential benefit of arthroscopic surgery for osteoarthritic knee associated with medial meniscus tear is controversial.This study was conducted to determine the effect of pre-operative medial meniscus extrusion(MME)on arthroscopic surgery outcomes in the osteoarthritic knee associated with medial meniscus tear during a minimum 4-year follow-up.Methods:This was a retrospective review of a total of 131 patients diagnosed with osteoarthritic knee associated with medial symptomatic degenerative meniscus tear who underwent arthroscopic surgery from January 2012 to December 2014 and were observed for more than 4 years.Patients were classified into two groups:MME≥3mm(major MME group,n=54)and MME<3mm(non-major MME group,n=77).Clinical assessments,including the Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)score,and radiographic assessments,including the Kellgren-Lawrence(K-L)grade and medial joint space width(JSW),were evaluated pre-operatively and at final follow-up.The longitudinal changes of clinical and radiographic parameters(WOMAC and the medial JSW change,K-L grade progression)were compared between groups unadjusted and adjusted for age,sex,and body mass index.Four-year survival rates(without progression to knee replacement[KR])were also evaluated using a log-rank test and Cox proportional hazard regression model.Results:Major MME was present in 41%of patients.After a minimum 4-year follow-up,the mean WOMAC total and pain scores improved significantly in both groups.However,the medial JSW and K-L grade worsened significantly.Patients with pre-operative majorMMEworsened more inWOMACtotal(adjusted mean difference[MD]3.800,95%confidence interval[CI]:0.900,11.400;P=0.037)and function(adjusted MD 3.100,95%CI:0.700,6.300;P=0.038)scores than patients with pre-operative non-major MME,and no significant difference was observed inWOMACpain and stiffness score between groups.The group with majorMME had significantly higher joint space narrowing(adjusted MD 0.630,95%CI: 1.250, 0.100;P=0.021)and K-L rate progression(adjusted mean relative risk[RR]1.310,95%CI:1.100,1.600;P=0.038)than the group with non-major MME.There was a significantly more KR progression in patients with major MME compared with those with non-major MME(adjusted RR 3.100,95%CI:1.100,9.200;P=0.042 and adjusted hazard ratio 3.500,95%CI 1.100,9.500;P=0.022).Conclusions:Osteoarthritic knee patients associated with medial meniscus tear with non-major MME are more responsive to arthroscopic surgery in terms of the clinical and radiologic outcomes and survival for at least 4-year follow-up;however,in terms of pain relief,arthroscopic surgery in patients with major MME is also beneficial as well as in patients with non-major MME.

Optimized Combinatorial Properties of an AlMgSi(Cu) Alloy Achieved by a Mechanical-Thermal Combinatorial Process

Enhancing combinatorial properties,such as excellent corrosion resistance,high strength and good ductility combined,is an important issue for manufacturing high-quality AlMgSi(Cu)alloys.Here,we show that this can be achieved by optimizing a combinatorial process consisting of pre-ageing,cold-rolling and post-ageing to tailor the hierarchical microstructures of the alloy.Transmission electron microscopy analysis reveals that the enhanced combinatorial properties of corrosion resistance,strength and ductility are owing to modification of grain boundary microstructure in good association with changes of precipitate microstructures and a more homogenous distribution of solute atoms,as compared with the microstructures of the alloy processed by thermal ageing only.