OBJECTIVE: To observe the improvement effects of angiotensin converting enzyme inhibitor (ACEI) fosinopril, perindopril and benazepril on ventricular remodeling in patients with acute myocardial infarction (AMI), and to evaluate its safety. METHODS: A total of 96 AMI patients selected from our hospital during Jan. 2014-Oct. 2016 were divided into group A, B, C according to random number table, with 32 cases in each group. All patients received symptomatic treatment, underwent percutaneous coronary intervention, and then given ACEI after blood vessels recanalization and keeping blood pressure stable. Group A was given Fosinopril sodium tablets 10 mg, qd; group B was given Perindopril tert-butylamine tablets 4 mg, qd; group C was given Benazepril hydrochloride tablets 10 mg, qd. All groups were treated for consecutive 6 months. Cardiac structure and function indexes (LVESD, LVEDD, IVSD, LVPWD, LVEF, CO), hemodynamic indexes (SBP, DBP, HR) and related lab indexes (FPG, TG, TC, HDL-C, LDL-C, AST, ALT, Scr, BUN) of 3 groups were observed before and after treatment. The occurrence of ADR was recorded. RESULTS: Before treatment, there was no statistical significance in cardiac structure and function indexes, hemodynamic indexes or related lab indexes among 3 groups (P＞0. 05). After treatment, the levels of LVESD, LVEDD, LVPWD, CO, HR, FPG, TG, TC and LDL-C in 3 groups were decreased significantly, while the levels of LVEF and SBP were increased significantly, with statistical significance (尸＜0. 05). There was no statistical significance in above indexes among 3 groups after treatment (P＞0. 05). After treatment, the level of Scr in group B was significantly increased and higher than group A and C, with statistical significance (P＜0. 05). There was no statistical significance in the levels of IVSD, DBP, HDL-C, AST, ALT or BUN among 3 groups before and after treatment as well as the level of Scr between group A and C (P＞ 0. 05). There was no statistical significance in the incidence of ADR among 3 groups(P＞0. 05). CONCLUSIONS: Fosinopril, perindopril and benazepril can significantly improve ventricular remodeling in AMI patients, narrowing the heart cavity, increasing systolic pressure, lowering heart rate, reducing the oxygen consumption of the ventricle, with similar effects. Perindopril may increase the level of Scr, so fosinopril and benazepril are safe and suitable for AMI patients with renal function disorder.

Objective To study mechanical properties of porous scaffolds with lattice Weaire-Phelan (LWP) structure and precisely simulate the whole process of compression test using finite element method. Methods The Ti6Al4V (TC4) porous scaffolds with different porosities were manufactured by selective laser melting (SLM) technology, and their mechanical properties were measured by uniaxial compressive tests, and compared with those of human bones and porous scaffolds with other cellular structures. Four types of material models were verified for their effects on the simulation of porous scaffold compression. Results LWP samples presented the elastic modulus close to that of human cancellous bone and significantly higher yield strength than that of cortical bone in most parts of human body. Compared with other scaffold structures, LWP samples exhibited the lowest elastic modulus and highest yield strength. The simulated results derived from the proposed material model in this study, namely, Johnson-Cook constitutive model and failure model based on dynamic geometric strain (JCDG), were proved very consistent with the experimental data. Conclusions LWP scaffolds as the bone repair biomaterials exhibite more excellent mechanical properties than the scaffolds with other structures. JCDG is more beneficial for establishing the reasonable simulation model of porous scaffolds compression, compared with other reported material models.

Emerging SARS-CoV-2 variants have made COVID-19 convalescents susceptible to re-infection and have raised concern about the efficacy of inactivated vaccination in neutralization against emerging variants and antigen-specific B cell response. To this end, a study on a long-term cohort of 208 participants who have recovered from COVID-19 was conducted, and the participants were followed up at 3.3 (Visit 1), 9.2 (Visit 2), and 18.5 (Visit 3) months after SARS-CoV-2 infection. They were classified into three groups (no-vaccination (n = 54), one-dose (n = 62), and two-dose (n = 92) groups) on the basis of the administration of inactivated vaccination. The neutralizing antibody (NAb) titers against the wild-type virus continued to decrease in the no-vaccination group, but they rose significantly in the one-dose and two-dose groups, with the highest NAb titers being observed in the two-dose group at Visit 3. The NAb titers against the Delta variant for the no-vaccination, one-dose, and two-dose groups decreased by 3.3, 1.9, and 2.3 folds relative to the wild-type virus, respectively, and those against the Omicron variant decreased by 7.0, 4.0, and 3.8 folds, respectively. Similarly, the responses of SARS-CoV-2 RBD-specific B cells and memory B cells were boosted by the second vaccine dose. Results showed that the convalescents benefited from the administration of the inactivated vaccine (one or two doses), which enhanced neutralization against highly mutated SARS-CoV-2 variants and memory B cell responses. Two doses of inactivated vaccine among COVID-19 convalescents are therefore recommended for the prevention of the COVID-19 pandemic, and vaccination guidelines and policies need to be updated.