Role of Al in the Solution Strengthening of Mg–Al Binary Alloys

Mg–Al binary alloys in the concentration range from 0 to 4.0 wt.% Al have been prepared under conventional casting conditions. The as-cast Mg and Mg–Al alloys after solution treatment were processed via hot extrusion at 350 °C. The results show that Al has a positive influence on grain refinement and solution strengthening. The as-extruded Mg–Al alloys are fully recrystallized, and the tensile yield strength of the binary alloys is two times higher than that of pure Mg. Furthermore, the elongations of Mg–Al alloys are much higher than that of pure Mg. In addition, Mg and Mg–Al alloys were further studied by the viscoplastic self-consistent (VPSC) model to explore the activation and evolution of deformation modes. The simulation results match well with the experimental results

High intensity focused ultrasound treatment for adenomyosis: comparison of efficacy based on MRI features

AbstractObjective To compare the clinical efficacy of High intensity-focused ultrasound(HIFU) for different types of adenomyosis classified by magnetic resonance imaging (MRI).Methods A total of 227 patients with adenomyosis who underwent HIFU treatment in Suining Central Hospital from January 2014 to December 2019 were included. Based on the preoperative pelvic MRI examination and Kishi isometric classification method, the patients were divided into 4 types according to the location of lesions. There were 82 cases of type I (endogenous type), 75 cases of type II (exogenous type), 34 cases of type III (nodular type), and 36 cases of type IV (heterogeneous type). The results of HIFU treatment for four types of adenomyosis and intraoperative adverse effects were analyzed. The changes of lesion size, dysmenorrhea, and menstrual volume were analyzed at 3 and 6 months after the operation.Result (1) adverse effects: All patients successfully accepted HIFU treatment under sedation and analgesia. Grade A adverse effects occurred in 51 cases (22.47%) and grade B adverse effects in 3 cases (1.32%). The incidence of adverse effects in type I–IV patients was 21.95%, 22.66%, 23.53%, and 30.56%, respectively. There was no significant difference in the incidence of grade A and B adverse effects in all types, and no grade C–F adverse effects occurred. (2) Ablation effect: The ablation rate of type III(nodular type)patients was (74.7 ± 20.3) %, which was significantly higher than that of the other three types (p < .05). (3) Changes in lesion size: the lesion size of all patients decreased after treatment and the reduction rate gradually increased with time. At 6 months after the operation, the lesion reduction rate of type III patients was (70.8 ± 14.8) %, higher than that of the other three types patients (p < .05). There was no significant difference in the reduction rate of type I, type II and type IV. (4) Remission of menorrhagia: At 6 months after the operation, the total remission rate of type III patients was 100%, while the total remission rate of type IV patients (65.4%, 17/26) that was lower than that of type I, II and III patients(p < .05). (5) Dysmenorrhea relief: At 6 months after the operation, the total dysmenorrhea relief rate of type III patients was 100% and the complete relief rate (28.1%, 18/31) was higher than that of the other three types, which was significant differences (p < .05).Conclusions HIFU is safe and effective in the treatment of different types of adenomyosis, the therapeutic effect of HIFU in patients with type III adenomyosis is better than that of the other three types

High Intensity Focused Ultrasound Ablation for Juvenile Cystic Adenomyosis: Two Case Reports and Literature Review

Cystic adenomyosis is a rare type of uterine adenomyosis, mainly seen in young women, which is often characterized by severe dysmenorrhea. The quality of life and reproductive function of young women could be affected by misdiagnosis and delayed treatment. At present, there are no universal guidelines and consensus. We report two cases of patients with cystic adenomyosis in juveniles treated with high-intensity focused ultrasound (HIFU) ablation. In the first case, magnetic resonance imaging (MRI) indicated a cystic mass of 2.0 cm × 3.1 cm × 2.4 cm in the uterus. After she underwent HIFU treatment, her pelvic MRI showed a mass of 1.1 × 2.4 cm in size, and her dysmenorrhea symptoms gradually disappeared. In the second case, a pelvic MRI indicated a 5.1 cm × 3.3 cm × 4.7 cm cystic mass in the uterus. After she underwent HIFU and combined four consecutive cycles of GnRH-a treatment, the lesion shrunk 1.2 cm ×1.4 cm × 1.6 cm, without dysmenorrhea. Simultaneously, the report reviewed 14 cases of juvenile cystic adenomyosis over the last ten years. HIFU or HIFU-combined drugs were safe and effective in treating juvenile cystic adenomyosis, but multicenter and prospective studies may be necessary to validate this in the future

High temperature formability of graphene nanoplatelets-AZ31 composites fabricated by stir-casting method

Outstanding mechanical properties of graphene nanoplatelets (GNPs) make them ideal reinforcement for mass production of composites. In this research, the composites were fabricated by stir-casting method. GNPs were added in 1.5 and 3.0 wt.% into Mg–3wt.% Al–1wt.% Zn (AZ31) magnesium alloy. As cast ingots were preheated for one hour and extruded at 350 °C with extrusion ratio of 5.2:1. As extruded AZ31-GNPs composites were micro-structurally characterized with X-ray diffraction, optical microscopy and scanning electron microscopy. Vickers micro-hardness of synthesized materials was investigated both in parallel and perpendicular to extrusion directions. Room temperature mechanical testing revealed that with increasing GNP's content, tensile fracture strain was remarkably increased without significant compromise in tensile strength. Furthermore, as extruded AZ31-3GNPs composites were subjected to tensile testing at temperatures ranging from 75 °C to 300 °C with initial strain rate of 2 × 10−3 s−1 to evaluate high temperature formability of composite. It was found that like CNTs, GNPs also have the potential to sustain tensile strength at high temperatures

Effect of boron on the grain refinement and mechanical properties of as-Cast Mg alloy AM50

The effect of B addition on the microstructure and mechanical properties of AM50 was investigated, and the mechanism of grain refinement was clarified. Optical microscopy, X-ray diffraction, scanning electron microscopy, and electron probe microanalysis were used to characterize the microstructure evolution. The grain size of as-cast AM50 decreased from 550 m to 100 m with the B content increasing from 0 to 0.15 wt.%. AlB2 particles in the Al-3B master alloy transformed to Mg-B, and acted as the grain refiner. The addition of B to as cast AM50 alloy results in improved mechanical properties of AM50 + xB alloys. For instance, the YTS (yield tensile strength), UTS (ultimate tensile strength), and elongation of as cast AM50 + 0.15 wt.% B alloy was 94 MPa, 215 MPa, and 12.3%