ABSTRACT
INTRODUCTION The efficacy and safety of low- and standard-dose alteplase for acute ischemic stroke (AIS) have not been consistently compared in previous studies. Nevertheless, the distinctions in the effects of low- and standard-dose alteplase, particularly within the context of bridging therapy (BT) for large vessel occlusion (LVO), warrant further exploration. This study compared clinical outcomes between BT with low- and standard-dose alteplase in patients with LVO-related AIS. METHODS We performed a search for randomized controlled trials and prospective or retrospective cohort studies investigating the clinical outcomes of BT in AIS in the PubMed, Embase, and Cochrane Library databases from inception to November 2022. The outcomes of interest were 90-day functional independence, successful recanalization, symptomatic intracerebral hemorrhage (sICH) and mortality; these outcomes were compared between patients who received BT with low- (primarily 0.6 mg/kg) and standard-dose alteplase (0.9 mg/kg). We used the standard-dose group as the reference and calculated the odds ratio (OR) and its 95% confidence interval (CI) from the raw numbers. Meta-analysis and ethnicity-based subgroup analysis (Asian and non-Asian) were performed. RESULTS Five observational studies, published after 2017 and including 408 patients, were included. The meta-analysis results demonstrated that compared with BT with standard-dose alteplase, BT with low-dose alteplase did not improve 90-day functional independence (odds ratio, [OR] 1.02; 95% confidence interval [CI], 0.58-1.80). Nevertheless, BT with low-dose alteplase was associated with a comparable successful recanalization rate (OR, 1.35; 95% CI, 0.68-2.67) and similar sICH incidence (OR 0.36; 95% CI, 0.10-1.36), and mortality (OR, 0.64; 95% CI, 0.27-1.54) compared with BT with standard-dose alteplase; however, the above three results were nonsignificant. In the ethnicity-based subgroup analyses, no differences were noted between Asian and non-Asian participants. CONCLUSIONS In patients with LVO-related AIS, BT with low- or standard-dose alteplase may provide similar efficacy, with no significant differences in sICH incidence and mortality. Additional well-designed prospective studies are required to confirm this result.
ABSTRACT
In this study, we designed a novel hybrid underwater sound-absorbing material of the metastructure that contains a viscoelastic substrate with a microperforated panel. Two types of sound-absorbing metastructures were combined to achieve satisfactory sound absorption performance in the low-frequency range. A homogenized equivalent layer and the integrated transfer matrix method were used to theoretically evaluate the sound absorption performance of the designed nonhomogeneous hybrid metastructure. The theoretical results were then compared with the results obtained using the finite-element method. The designed hybrid sound-absorbing metastructure exhibited two absorption peaks because of its different sound-absorbing mechanisms. The acoustic performance of the developed metastructure is considerably better than that of a traditional sound absorber, and the sound absorption coefficient of the developed metastructure is 0.8 in the frequency range of 3-10 kHz. In addition, an adjustment method for the practical underwater application of the designed metastructure is described in this research. Further studies show that the sound absorption coefficient of the adjusted metastructure still has 0.75 in the frequency range of 3-10 kHz, which indicates that this metastructure has the potential to be used as an underwater sound-absorbing structure. The results of this study can be used as a reference in the design of other novel hybrid underwater sound-absorbing structures.
