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Objective To summarize the characteristics of cognitive function and sleep structure in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) and to explore the correlation between them. Methods Total 73 patients with iRBD who visited Fujian Medical University Union Hospital from August 2018 to August 2021 were included, all of whom underwent neuropsychological tests and polysomnography monitoring. Pearson and partial correlation analyses were used to explore correlation between cognitive function and sleep structure parameters. Results 1) Neuropsychological tests: iRBD patients had lower Mini ⁃ Mental State Examination (MMSE; t = ⁃ 3.703, P = 0.000), Montreal Cognitive Assessment (MoCA; t = ⁃ 4.811, P = 0.000), Verbal Fluency Test (VFT)⁃number of correct words (t = ⁃ 2.171, P = 0.032) than control group. Trail Making Test (TMT)⁃A (t = 2.500, P = 0.014), TMT⁃B (t = 2.430, P = 0.016) and Stroop Color Word Test (SCWT)⁃A (t = 2.507, P = 0.013), SCWT⁃B (t = 15.042, P = 0.000), SCWT⁃ C (t = 27.228, P = 0.000) completion times were longer than control group. 2) Polysomnography monitoring: total sleep time (t = 2.699, P = 0.008), sleep efficiency (Z = ⁃ 2.103, P = 0.035), number of sleep stage transitions (t = 3.965, P = 0.000), proportion of non⁃rapid eye movement sleep stage 1 (N1 stage) to total sleep time (t = 2.887, P = 0.005), periodic limb movement of sleep index (PLMSI; t = ⁃ 2.917, P = 0.004), periodic limb movement⁃related arousal index (Z = ⁃ 2.291, P = 0.022), and total arousal index (Z = ⁃ 2.609, P = 0.009) were higher than those in control group, and the time of wakefulness after sleep was less than those in control group (t = ⁃ 2.230, P = 0.027). 3) Correlation between cognitive function and sleep structure parameters: MoCA score was negatively correlated with the percentage of N1 stage (r = ⁃ 0.184, P = 0.035), and positively correlated with the percentage of N2 stage (r = 0.173, P = 0.049); SCWT⁃B completion time was negatively correlated with the number of awakenings (r = ⁃ 0.186, P = 0.033); SCWT⁃C completion time was positively correlated with the number of sleep phase transitions (r = 0.212, P = 0.015) and the percentage of N1 stage (r = 0.181, P = 0.039); VFT⁃number of correct words was negatively correlated with the periodic limb movement of wake index (PLMWI; r = ⁃ 0.216, P = 0.018); the number of correct China⁃Rey Auditory Verbal Learning Test (C⁃RAVLT) immediate recall was positively correlated with the rapid eye movement (REM) sleep latency (r = 0.183, P = 0.045); the number of correct C⁃RAVLT delay recall was negatively correlated with the PLMWI (r = ⁃ 0.196, P = 0.032) and PLMSI (r = ⁃ 0.180, P = 0.049); the Clock Drawing Test was positively correlated with sleep latency (r = 0.192, P = 0.035) and REM sleep latency (r = 0.199, P = 0.029), and negatively correlated with the percentage of REM sleep (r = ⁃ 0.189, P = 0.038). The Beck Depression Inventory (BDI) score was positively correlated with total sleep time (r = 0.347, P = 0.000), sleep efficiency (r = 0.319, P = 0.000) and the percentage of REM sleep (r = 0.204, P = 0.026), and negatively correlated with the time of wakefulness after sleep (r = ⁃ 0.280, P = 0.002) and the percentage of N1 stage (r = ⁃ 0.299, P = 0.001). Conclusions Patients with iRBD have cognitive dysfunction mainly manifested by decreased attention, executive function and language function, and sleep structural disorders may affect the cognitive function of such patients.

Vacuum preloading combined with prefabricated vertical drains (PVDs) has been widely used to improve soft clayey soil deposits. However, the consolidation deformation of high-water-content slurry under vacuum pressure is still not fully understood. In this study, the displacement field of the slurry during vacuum preloading was directly observed using the particle image velocimetry (PIV) technique. The test results showed that the displacement field of the slurry could be divided into three different zones that reflect distinct consolidation patterns. In zones I and III, the slurry was predominantly compressed along the horizontal and vertical directions, respectively, whereas in zone II, compression occurred in both vertical and horizontal directions. In particular, the slurry elements in zones I and II underwent horizontal extension prior to horizontal compression. The study also visualized the boundary of the soil column and provided an equation for the relation between soil column thickness and consolidation time, which could provide a reference for the theoretical consolidation calculations related to soil columns. Key words: dredged slurry, vacuum preloading, particle image velocimetry, PIV, deformation, soil column. Le prechargement par le vide combine a des drains verticaux prefabriques (PVD) a ete largement utilise pour ameliorer les depots de sols argileux mous. Cependant, la deformation de consolidation d'une boue a forte teneur en eau sous pression sous vide n'est pas encore totalement comprise. Dans cette etude, le champ de deplacement de la boue pendant le prechargement sous vide a ete directement observe en utilisant la technique de velocimetrie par image de particules (PIV). Les resultats des essais ont montre que le champ de deplacement de la boue pouvait etre divise en trois zones differentes qui refletent des modeles de consolidation distincts. Dans les zones I et III, la boue a ete principalement comprimee dans les directions horizontale et verticale, respectivement, tandis que dans la zone II, la compression a eu lieu dans les deux directions, verticale et horizontale. En particulier, les elements de boue des zones I et II ont subi une extension horizontale avant la compression horizontale. L'etude a egalement permis de visualiser la limite de la colonne de sol et de fournir une equation pour la relation entre l'epaisseur de la colonne de sol et le temps de consolidation, qui pourrait servir de reference pour les calculs theoriques de consolidation lies aux colonnes de sol. [Traduit par la Redaction] Mots-cles : boue de dragage, prechargement sous vide, velocimetrie par image de particules, PIV, deformation, colonne de sol., Introduction Land reclamation is an effective measure to address land shortages in coastal counties. The raw material used for land reclamation is usually dredged slurry with a high water content [...]

As nanoscale reinforcements, the graphene and graphene oxide nanoplates exhibit distinct mechanical and physical properties. The determination of the effective elasto-plastic behavior of nanoplate/ceramic nanocomposites and the different filling effects of graphene and graphene oxide nanoplate deserve systematic investigation. In this work, we intend to uncover how the graphene and graphene oxide nanoplates affect the macroscopic elasto-plastic characteristics of ceramic matrix nanocomposites and what differences in both nanoplates enhancements. A homogenization model is first utilized for determining the effective elastic parameters of nanoplate/ceramic composite with a perfect interface. Then the slightly weakened interface model is introduced to characterize the sliding effects of nanoplates in a ceramic matrix, and the effective elastic parameters of such nanoplates filled composites incorporating the interfacial sliding effects are explicitly formulated. Furthermore, a nonlinear micromechanics model is developed to investigate the macroscopic elastoplasticity and the yield behavior of graphene and graphene oxide nanoplate-filled ceramic nanocomposites subjected to confining pressure. The filling effects of the two kinds of nanoplates on the mechanical properties of such nanocomposite are comparatively examined. The calculated results demonstrate that types of the nanoplates and the imperfect interfaces between nanoplates and ceramic matrix have significant influences on the effective elasto-plastic behaviors of the nanoplate composites.

In the process of treating the dredged slurry under vacuum preloading combined with the prefabricated vertical drains (PVDs), a dense “soil column” with low permeability will be formed around the PVD, which results in a poor drainage condition and an unsatisfactory treatment (i.e., the clogging effect). In this study, in order to predict the consolidation behavior of dredged slurry with different initial water contents, the compressibility and permeability of dredged slurry with different initial water contents are investigated. Based on the compression and permeability curves obtained by laboratory tests, the analytical solution to soil consolidation under vacuum preloading is derived. Both the clogging effect and the effect of the initial water content on the initial effective stress are considered. The developed analytical solution is validated through a series of consolidation tests of dredged slurry under vacuum preloading with different initial water contents. It shows that at a given vacuum preloading, the dissipation rate of excess pore water pressure in the dredged slurry decreases as the initial water content increases. The proposed analytical solution presents reliable predictions on the variation of settlement and degree of consolidation with time in the dredged slurry with different initial water contents under vacuum preloading.

Laboratory tests have been carried out for simulating dredged-slurry treatment combining air-booster and conventional vacuum preloading methods. Settlement plate, micro pore water pressure transducer and miniature vane shearing instrument are adopted for monitoring the settlement, the pore pressure dissipation and the soil strength during the test. The tests results demonstrate that the air-booster vacuum-preloading method can significantly improve the soil strength, pore-water pressure dissipation and settlement. In particular, the real-time responses of pore-water pressure during the air-pressurizing process have been obtained that, in combination with the numerical simulations, help derive the reinforcement mechanism of the air-booster vacuum preloading method, which involves using micro cracks generated by splitting soil between the booster tube and PVD using the pressurised air. Those cracks improve the soil permeability, and have lasting effect even after air pressuring ceased.

BACKGROUND Eco-functional areas play an important role in soil and water conservation and biodiversity conservation. The Wushui River is a watershed located in the Nanling ecological function area. However, study on the content and potential ecological risk of heavy metals in the soil of the upstream area of the watershed is scarce. OBJECTIVES To investigate the degree of heavy metals pollution and the potential ecological risk of soils in the upper reaches of the Wushui River. METHODS The soil samples of five land utilization types in the upper reaches of the Wushui River Basin, including mining, industrial, and cultivated land and forest, were collected to analyze the contents of seven heavy metals Cd, As, Cu, Hg, Ni, Pb and Zn in the soil. The Nemerow comprehensive pollution index was used to evaluate the degree of heavy metal pollution, and the Hakanson potential ecological risk index was used to evaluate the potential ecological risk of heavy metals in soil. Principal component analysis was used to investigate the source of heavy metal pollution. RESULTS The results show that the average concentrations of Cd, As, Cu, Hg, Ni, Pb and Zn in the upper reaches of the Wushui River were 1.28, 72.44, 54.62, 0.27, 68.32, 72.29 and 158.42mg/kg, respectively, which higher than the soil background values. The contents of the heavy metals, except mercury in mining land, were higher than those in other types of soils. The single factor pollution index of heavy metals in the mean state show that Cd and As were heavy pollution elements with factors of 5.07 and 3.25, respectively. In mining land, the Cd single factor pollution index reached 13.59. Heavy metal pollution in mining land was the most serious, followed by industrial land. Forest was in a safe state. Potential ecological hazard index evaluation results showed that Cd reached a very strong ecological hazard and As was a strong ecological hazard in mining land. Mining land and industrial land reached a strong ecological hazard, industrial land reached a moderate ecological hazard, and other types of soils were slightly ecologically harmful. The results showed that As, Cd, Cu and Zn came from industrial and mining activities, Ni and Hg mainly came from parent materials, and Pb came from transportation. CONCLUSIONS Heavy metal pollution of soil is relatively serious in the upstream area of the Wushui River Basin. Cd and As are the main risk factors in the area, mainly deriving from mining and industrial activities.