Ginkgo biloba extracts (GBEs) have been recommended to improve cognitive function and to prevent cognitive decline, but earlier evidence was inconclusive. Here, we evaluated all systematic reviews of GBEs for prevention of cognitive decline, and intervention of mild cognitive impairment (MCI) and dementia. Six databases from their inception to September 2015 were searched. Ten systematic reviews were identified, including reviews about Alzheimer's disease (n = 3), about vascular dementia (n = 1), about both Alzheimer's disease and vascular dementia (n = 2), about Alzheimer's disease, vascular dementia and mixed dementia (n = 3), and a review about MCI (n = 1). Based on the overview quality assessment questionnaire, eight studies were scored with at least 5 points, while the other two scored 4 points and 3 points, respectively. Medication with GBEs showed improvement in cognition, neuropsychiatric symptoms, and daily activities, and the effect was dose-dependent. Efficacy was convincingly demonstrated only when high daily dose (240 mg) was applied. Compared with placebo, overall adverse events and serious adverse events were at the same level as placebo, with less adverse events in favor of GBE in the subgroup of Alzheimer's disease patients, and fewer incidences in vertigo, tinnitus, angina pectoris, and headache. In conclusion, there is clear evidence to support the efficacy of GBEs for MCI and dementia, whereas the question on efficacy to prevent cognitive decline is still open. In addition, GBEs seem to be generally safe.

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Resting-state functional near infrared spectroscopy (fNIRS) scanning has attracted considerable attention in stroke rehabilitation research in recent years. The aim of this study was to quantify the reliability of fNIRS in cortical activity intensity and brain network metrics among resting-state stroke patients, and to comprehensively evaluate the effects of frequency selection, scanning duration, analysis and preprocessing strategies on test-retest reliability. Nineteen patients with stroke underwent two resting fNIRS scanning sessions with an interval of 24 hours. The haemoglobin signals were preprocessed by principal component analysis, common average reference and haemodynamic modality separation (HMS) algorithm respectively. The cortical activity, functional connectivity level, local network metrics (degree, betweenness and local efficiency) and global network metrics were calculated at 25 frequency scales × 16 time windows. The test-retest reliability of each fNIRS metric was quantified by the intraclass correlation coefficient. The results show that (1) the high-frequency band has higher ICC values than the low-frequency band, and the fNIRS metric is more reliable than at the individual channel level when averaged within the brain region channel, (2) the ICC values of the low-frequency band above the 4-minute scan time are generally higher than 0.5, the local efficiency and global network metrics reach high and excellent reliability levels after 4 min (0.5 < ICC < 0.9), with moderate or even poor reliability for degree and betweenness (ICC < 0.5), (3) HMS algorithm performs best in improving the low-frequency band ICC values. The results indicate that a scanning duration of more than 4 minutes can lead to high reliability of most fNIRS metrics when assessing low-frequency resting brain function in stroke patients. It is recommended to use the global correction method of HMS, and the reporting of degree, betweenness and single channel level should be performed with caution. This paper provides the first comprehensive reference for resting-state experimental design and analysis strategies for fNIRS in stroke rehabilitation.

Background Since 2019, the COVID-19 outbreak has spread around the world, and health care workers, as frontline workers, have faced tremendous psychological stress. Objective The purpose of this study is to explore whether web-based mindfulness-based interventions continue to have a positive impact on anxiety, depression, and stress among health care workers during the COVID-19 pandemic. Methods The inclusion criteria were as follows: (1) participants were frontline health care workers during the COVID-19 pandemic; (2) the experimental group was a web-based mindfulness-based intervention; (3) the control group used either general psychological intervention or no intervention; (4) outcome indicators included scales to assess anxiety, depression, and stress; and (5) the study type was a randomized controlled study. Studies that did not meet the above requirements were excluded. We searched 9 databases, including Web of Science, Embase, PubMed, Cochrane Library, Scopus, ScienceDirect, SinoMed, China National Knowledge Infrastructure (CNKI), and Wanfang Database, for randomized controlled studies on the effects of web-based mindfulness-based interventions on common mental disorder symptoms among health care workers from January 1, 2020, to October 20, 2022. The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database scale. The Cochrane risk of bias tool was used to assess the risk of bias. Subgroup analysis was used to look for sources of heterogeneity and to explore whether the results were the same for subgroups under different conditions. Sensitivity analysis was used to verify the stability of the pooled results. Results A total of 10 randomized controlled studies with 1311 participants were included. The results showed that web-based mindfulness-based interventions were effective in reducing the symptoms of anxiety (standard mean difference [SMD]=–0.63, 95% CI –0.96 to –0.31, P<.001, I2=87%), depression (SMD=–0.52, 95% CI –0.77 to –0.26, P<.001, I2=75%), and stress (SMD=–0.20, 95% CI –0.35 to –0.05, P=.01, I2=58%) among health care workers during the COVID-19 pandemic, but with wide CIs and high heterogeneity. Conclusions Web-based mindfulness-based interventions may be effective in reducing the symptoms of anxiety, depression, and stress among frontline health care workers during the COVID-19 pandemic. However, this effect is relatively mild and needs to be further explored by better studies in the future. Trial Registration PROSPERO CRD42022343727; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=343727