Rheumatoid arthritis is a protective factor against Alzheimer's disease: a bidirectional two-sample Mendelian randomization study.

BACKGROUND: Epidemiological evidence suggests that there is an association between rheumatoid arthritis (RA) and Alzheimer's disease (AD). However, the causal relationship between RA and AD remains unclear. Therefore, this study aimed to investigate the causal relationship between RA and AD. METHODS: Using publicly available genome-wide association study datasets, bidirectional two-sample Mendelian randomization (TSMR) was performed using the inverse-variance weighted (IVW), weighted median, MR‒Egger regression, simple mode, and weighted mode methods. RESULTS: The results of MR for the causal effect of RA on AD (IVW, odds ratio [OR] = 0.959, 95% confidence interval [CI]: 0.941-0.978, P = 2.752E-05; weighted median, OR = 0.960, 95% CI: 0.937-0.984, P = 0.001) revealed a causal association between genetic susceptibility to RA and an increased risk of AD. The results of MR for the causal effect of AD on RA (IVW, OR = 0.978, 95% CI: 0.906-1.056, P = 0.576; weighted median, OR = 0.966, 95% CI: 0.894-1.043, P = 0.382) indicated that there was no causal association between genetic susceptibility to AD and an increased risk of RA. CONCLUSIONS: The results of this two-way two-sample Mendelian randomization analysis revealed a causal association between genetic susceptibility to RA and a reduced risk of AD but did not reveal a causal association between genetic susceptibility to AD and an increased or reduced risk of RA.

[Rapid identification of chemical components in compound Nanxing acesodyne plaster by UPLC-Q-TOF-MS/MS].

The study aims to qualitatively analyze the chemical composition of compound Nanxing acesodyne plaster by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry( UPLC-Q-TOF-MS/MS). The analysis was performed on Agilent Zorbax SB-C_(18)( 4. 6 mm×250 mm,5 µm) column. The mobile phase consisted of methanol and 0. 2% formic acid-water was used as gradient elution. The flow rate was 1 mL·min~(-1) and column temperature was 30 ℃. The Mass spectrometry was acquired in both positive and negative ion modes using ESI. The components were identified by the precise mass-to-charge ratio,secondary fragmentation and other information combined with reference substance and literature data. As a result,58 compounds were identified and predicted,including alkaloids,flavonoids,coumarins,organic acids and lactone compounds,of which 12 compounds were verified by the reference substances. The results provide reference for the quality control of compound Nanxing acesodyne plaster,and lay the foundation for elucidating the active components mechanism.

The sand-deposition impact of artificial gravel beds on the protection of the Mogao Grottoes.

Gravel beds can prevent sand-dust emission and weaken sand-dust flux. We used wind-tunnel experiments and field observations on artificial gravel beds above the Mogao Grottoes to quantify their impact. In the report, we identified a significant correlation between gravel roughness and its ability to trap wind-transported sand. The optimal combinations of gravel diameter and coverage were determined. The greatest roughness is achieved when small gravel coverage is 75%, medium 40% and large 45%. We found that initial wind speed and gravel coverage are the key factors controlling the amount of sand trapped by the gravel beds.