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Rivers in karst areas face increased risks from persistent growth in human activity that leads to changes in water chemistry and threatens the water environment. In this study, principal component analysis (PCA), ion ratio measurements, and other methods were used to study the water chemistry of the Qingshuijiang River Basin over the past 10 years. The results showed that the main ions in the river were Ca2+ and HCO3–, with a cation order of Ca2+ (mean: 0.93 mmol/L) > Mg2+ (mean: 0.51 mmol/L) > Na+ (mean: 0.30 mmol/L) > K+ (mean: 0.06 mmol/L) and HCO3– (mean: 2.00 mmol/L) > SO42– (mean: 0.49 mmol/L) > Cl– (mean: 0.15 mmol/L) > NO3– (mean: 0.096 mmol/L) > F– (mean : 0.012 mmol/L). In the past 10 years, the concentration of major ions in the river water in the basin has increased significantly. The weathering input of rock (mainly upstream carbonate) was the main source of Mg2+, Ca2+, and HCO3−, though sulfuric acid was also involved in this process. While K+ and Na+ were affected by the combination of human activity and the weathering input of silicate rock in the middle and lower reaches of the river, human activity was the main source of SO42−, NO3−, and F− ions. Irrigation water quality and health risks were evaluated by calculating the sodium adsorption ratio (SAR), soluble sodium percentage (Na%), residual sodium carbonate (RSC), and hazard quotient (HQ). The findings indicated that the river water was generally safe for irrigation and drinking, and the health risks were gradually reduced over time. However, long-term monitoring of the river basin is still essential, especially for the risk of excessive F− in a few tributaries in the basin. [ABSTRACT FROM AUTHOR]

The cerebral lymphatic drainage plays an important role in the occurrence and development of central nervous system diseases. Recent studies have shown that cerebral lymphatic drainage is regulated by circadian rhythm and anesthesia state; however, the regulating mechanism is still unclear. In this study, we used the second near-infrared region in vivo imaging to explore the regulation of cerebral lymphatic drainage in mice at different states. At first, by injection of a tracer at different times, we confirmed that the drainage of the meningeal lymphatic system was the fastest at zeitgeber time 2, while the internal flow of the glymphatic system was the slowest. Under anesthesia with isoflurane, administration of dexmedetomidine, an anesthetic that inhibits norepinephrine (NE) release, enabled mice to enter the stage of non-rapid eye movement sleep, at which time the influx of the glymphatic system increased, the efflux of the meningeal lymphatic system decreased, and the clearance rate of the brain parenchyma decreased. However, following the exogenous NE supplement, mice quickly changed from a non-rapid eye movement stage into an awake state with the meningeal lymphatic drainage retrieval. The results showed whether the drainage of the glymphatic system and meningeal lymphatic vessels, or parenchymal clearance, has made rapid adjustments based on sleep status that is regulated by NE. This study reveals that the NE-regulated sleep–wake cycle is a powerful regulator of cerebral lymphatic drainage and provides a potential therapeutic target for related central nervous system diseases. [ABSTRACT FROM AUTHOR]

Skin aging is a complex physiological process, in which cells and the extracellular matrix (ECM) interreact, which leads to a change in the mechanical properties of skin, which in turn affects the cell secretion and ECM deposition. The natural skin microrelief that exists from birth has rarely been taken into account when evaluating skin aging, apart from the common knowledge that microreliefs might serve as the starting point or initialize micro-wrinkles. In fact, microrelief itself also changes with aging. Does the microrelief have other, better uses? In this paper, owing to the fast-developing 3D printing technology, skin wrinkles with microrelief of different age groups were successfully manufactured using the Digital light processing (DLP) technology. The mechanical properties of skin samples with and without microrelief were tested. It was found that microrelief has a big impact on the elastic modulus of skin samples. In order to explore the role of microrelief in skin aging, the wrinkle formation was numerically analyzed. The microrelief models of different age groups were created using the modified Voronoi algorithm for the first time, which offers fast and flexible mesh formation. We found that skin microrelief plays an important role in regulating the modulus of the epidermis, which is the dominant factor in wrinkle formation. The wrinkle length and depth were also analyzed numerically for the first time, owing to the additional dimension offered by microrelief. The results showed that wrinkles are mainly caused by the modulus change of the epidermis in the aging process, and compared with the dermis, the hypodermis is irrelevant to wrinkling. Hereby, we developed a hypothesis that microrelief makes the skin adaptive to the mechanical property changes from aging by adjusting its shape and size. The native-like skin samples with microrelief might shed a light on the mechanism of wrinkling and also help with understanding the complex physiological processes associated with human skin. [ABSTRACT FROM AUTHOR]

The liver and kidney are the major detoxifying organs in the human body and play an important role in pharmacokinetics. Drug-induced hepatotoxicity and nephrotoxicity can cause irreversible damage to the liver and kidney and are a major cause of drug failure in later stages. Both animal models and conventional cell culture have a number of limitations, such as animal ethics and gene mismatching and there is an urgent need to develop a new drug toxicity evaluation approach. In this paper, a 3D liver–kidney on a chip with a biomimicking circulating system (LKOCBCS) was constructed to obtain kidney and liver models in vitro for drug safety evaluation. LKOCBCS, which has a parallel circulating system mimicking biological circulation, consists of 3D biomimetic tissue of liver lobules similar to that of the human liver constructed by 3D bioprinting and renal proximal tubule barriers fabricated by ultrafast laser assisted etching. The proposed LKOCBCS facilitates the communication between the liver and the kidney, including the exchange of nutrients, compounds, and metabolites. The results revealed that the glucose concentration and cell metabolism stabilized after 7 days. A dynamically repeated low-dose administration of cyclosporine A (CsA) was fed to the system, and hepatotoxicity and nephrotoxicity were observed on day 3 according to the changes in toxicity markers. The high levels of drug induced biomarkers expressed in LKOCBCS indicate that this system is more sensitive than the monoculture liver chip and it is highly potential in replacing animal models for effective drug toxicity screening. [ABSTRACT FROM AUTHOR]