The effect of whole-body vibration on lower extremity function in children with cerebral palsy: A meta-analysis.

OBJECTIVE: The aim of this meta-analysis was to evaluate the effect of whole-body vibration training on lower limb motor function in children with cerebral palsy in randomized-controlled trials (RCTs). METHODS: Two independent reviewers systematically searched the records of nine databases (PubMed, Cochrane, Web of Science, EMBASE, CNKI, etc.) from inception to December 2022. Tools from the Cochrane Collaboration were used to assess risk of bias. Standard meta-analyses were performed using Stata 16.0 and Revman 5.3. For continuous variables, the arms difference was calculated as the weighted mean difference (WMD) between the values before and after the intervention and its 95% confidence interval (95% CI). RESULTS: Of the 472 studies identified, 13 (total sample size 451 participants) met the inclusion criteria. Meta-analysis showed that WBV training could effectively improve GMFM88-D [WMD = 2.46, 95% CI (1.26, 3.67), P<0.01] and GMFM88-E [WMD = 3.44, 95% CI (1.21, 5.68), P = 0.003], TUG [WMD = -3.17, 95% CI (-5.11, -1.24), P = 0.001], BBS [WMD = 4.00,95% CI (3.29, 4.71), P<0. 01] and the range of motion of ankle joint and the angle of ankle joint during muscle reaction in children with cerebral palsy. The effect of WBV training on 6MWT walking speed [WMD = 47.64, 95% CI (-25.57, 120.85), p = 0.20] in children with cerebral palsy was not significantly improved. CONCLUSION: WBV training is more effective than other types of conventional physical therapy in improving the lower limb motor function of children with cerebral palsy. The results of this meta-analysis strengthen the evidence of previous individual studies, which can be applied to the clinical practice and decision-making of WBV training and rehabilitation in children with cerebral palsy.

Association between sedentary behavior and risk of cognitive decline or mild cognitive impairment among the elderly: a systematic review and meta-analysis.

Background: Existing evidence on the association between sedentary behavior (SB) and cognitive function remains inconclusive. Therefore, this study investigated the association between SB and the risk of cognitive decline (CD) or mild cognitive impairment (MCI) in the elderly. Methods: A comprehensive search was independently conducted by two researchers (XC and GQ) in seven electronic databases, including Medline (via PubMed), China Biology Medicine, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang database, and VIP database for Chinese technical periodicals, covering studies published from the inception of database to June 2023. Studies that investigated the relationship between SB and the risk of CD or MCI in the elderly were included. The quality of the literature was assessed using the Newcastle-Ottawa Scale (NOS) and the Agency for Healthcare Research and Quality (AHRQ) assessment tools. The combined effect size analysis, subgroup analysis, and publication bias assessment were performed using STATA 14.0. Results: A total of 13 cross-sectional and 6 cohort studies involving 81,791 individuals were included, comprising 17 high-quality studies and 2 medium-quality studies. We found that SB was significantly associated with an increased risk of CD [odds ratio (OR) = 1.69, 95% confidence intervals (CI): 1.47-1.94] or MCI (OR = 1.34, 95% CI: 1.14-1.56) among the elderly. Subgroup analysis stratified according to comorbidity, lifestyle, family structure, publication year, and region showed statistical differences between groups, and the consistency of the results revealed the sources of the heterogeneity. Conclusion: This meta-analysis showed that SB is positively associated with the risk of CD or MCI in the elderly, providing a higher level of evidence for the promotion of healthy behaviors by clinicians and health policymakers. Due to the number and quality of the included articles, more high-quality longitudinal studies are needed to further confirm our findings.

Effect of process parameters on microstructures and properties of Al-42Si alloy fabricated by selective laser melting.

In this paper, high-silicon Al-42Si alloy was prepared by selective laser melting (SLM) with different process parameters. Microstructures evolution and defects formation were studied and process parameters were optimized. The results shown that the density of SLM-fabricated Al-42Si alloy increases as input energy density increases. The highest and lowest density of SLM-fabricated Al-42Si alloy are obtained, when input energy density is 42.9J/mm3 and 33.8J/mm3 respectively. The microstructures of Al-42Si alloy fabricated by selective laser melting is mainly composed of primary silicon phase and eutectic silicon phase, which is distinct from casting alloy because of diffient grains size and shapes of the primary silicon. With higher energy density, larger size of the primary silicon observed during process due to higher heat released by powder. The size of primary silicon phase particles is in the range of 2.9-9.4µm, and the size of molten pool during SLM process is in the range of 125 ± 10µm-140 ± 10µm in this study. Also the hardness of SLM-fabricated Al-42Si alloy increases as input energy density increases between 40.0J/mm3 and 42.9J/mm3. After heat treatment, the residual stress is eliminated, microstructure stability and homogeneous of SLM-fabricated Al-42Si alloy are improved. The silicon distribution is more uniform and sizes increases about 1∼2µm, and the hardness decreases after heat treatment. The optimal SLM parameters for Al-42Si alloy are laser power of 320W, scanning speed of 1355 mm/s, layer thickness of 50µm and scanning space of 110µm.

Which gait training intervention can most effectively improve gait ability in patients with cerebral palsy? A systematic review and network meta-analysis.

Background: A vital objective to treat people with cerebral palsy (CP) is to increase gait velocity and improve gross motor function. This study aimed to evaluate the relative effectiveness of gait training interventions for persons with CP. Methods: Studies published up to October 26, 2022 were searched from four electronic databases [including Medline (via PubMed), Web of Science, Embase and Cochrane]. Studies with randomized controlled trials (RCTs), people with CP, comparisons of different gait training interventions and outcomes of gait velocity and gross motor function measures (GMFM) were included in this study. The quality of the literature was evaluated using the risk of bias tool in the Cochrane Handbook, the extracted data were analyzed through network meta-analysis (NMA) using Stata16.0 and RevMan5.4 software. Results: Twenty RCTs with a total of 516 individuals with CP were included in accordance with the criteria of this study. The results of the NMA analysis indicated that both external cues treadmill training (ECTT) [mean difference (MD) = 0.10, 95% confidence interval CI (0.04, 0.17), P < 0.05] and partial body weight supported treadmill training (BWSTT) [MD = 0.12, 95% CI (0.01, 0.23), P < 0.05] had better gait velocity than over ground gait training (OGT), BWSTT [MD = 0.09, 95%CI(0.01,0.18), P < 0.05] had a better gait velocity than robot-assisted gait training (RAGT), BWSTT [MD = 0.09, 95% CI (0.06, 0.13) P < 0.05] had a better gait velocity than treadmill training (TT), and BWSTT [MD = 0.14, 95% CI (0.07, 0.21), P < 0.05] had a better gait velocity than conventional physical therapy (CON). The SUCRA ranking indicated that BWSTT optimally improved the gait velocity, and the other followed an order of BWSTT (91.7%) > ECTT (80.9%) > RAGT (46.2%) > TT (44%) > OGT (21.6%) > CON (11.1%). In terms of GMFM, for dimension D (GMFM-D), there was no statistical difference between each comparison; for dimension E (GMFM-E), RAGT [MD = 10.45, 95% CI (2.51, 18.40), P < 0.05] was significantly more effective than CON. Both SUCRA ranking results showed that RAGT improved GMFM-D/E optimally, with rankings of RAGT (69.7%) > TT (69.3%) > BWSTT (67.7%) > OGT (24%) > CON (20.3%), and RAGT (86.1%) > BWSTT (68.2%) > TT (58%) > CON (20.1%) > OGT (17.6%) respectively. Conclusion: This study suggested that BWSTT was optimal in increasing the gait velocity and RAGT was optimal in optimizing GMFM in persons with CP. Impacted by the limitations of the number and quality of studies, randomized controlled trials with larger sample sizes, multiple centers, and high quality should be conducted to validate the above conclusion. Further studies will be required to focus on the total duration of the intervention, duration and frequency of sessions, and intensity that are optimal for the promotion of gait ability in this population. Systematic review registration: https://doi.org/10.37766/inplasy2022.10.0108, identifier: INPLASY2022100108.

Effect of growth rate on microstructure evolution in directionally solidified Ti-47Al alloy.

The microstructures and morphologies of directionally solidified Ti-47Al alloys with different growth rates ranging from 1 to 200 µm/s were investigated using the Bridgman directionally solidified method. The results showed that numerous columnar grains were formed along the growth direction with the onset of directional solidification. With a variation in the growth rate, the solid/liquid interface changed from a flat to cellular and to dendritic interface. The flat-to-cellular interface transition rate of the Ti-47Al alloy varied from 1 to 3 µm/s. When the growth rate was higher than 10 µm/s, the solid/liquid interface showed typical dendritic growth. During the directional solidification process, the main phase of the directionally solidified Ti-47Al alloy was the α phase, which can be attributed to the solute segregation, supercooling of the components, and contamination of the alloy melt by the Y2O3 ceramic shell. After reaching the steady growth state during the directional solidification process, the solidification path of the alloy was: L→α→α+γ→(α2+γ) + γ. With an increase in the growth rate, the primary dendrite spacing (λ) and lamellar spacing (λs) of the alloy decreased gradually.