Saikosaponins induced hepatotoxicity in mice via lipid metabolism dysregulation and oxidative stress: a proteomic study

Background Radix Bupleuri (RB) has been popularly used for treating many liver diseases such as chronic hepatic inflammation and viral Hepatitis in China. Increasing clinical and experimental evidence indicates the potential hepatotoxicity of RB or prescriptions containing RB. Recently, Saikosaponins (SS) have been identified as major bioactive compounds isolated from RB, which may be also responsible for RB-induced liver injury. Methods Serum AST, ALT and LDH levels were determined to evaluate SS-induced liver injury in mice. Serum and liver total triglyceride and cholesterol were used to indicate lipid metabolism homeostasis. Liver ROS, GSH, MDA and iNOS were used to examine the oxidative stress level after SS administration. Western blot was used to detect CYP2E1 expression. A 8-Plex iTRAQ Labeling Coupled with 2D LC - MS/MS technique was applied to analyze the protein expression profiles in livers of mice administered with different doses of SS for different time periods. Gene ontology analysis, cluster and enrichment analysis were employed to elucidate potential mechanism involved. HepG2 cells were used to identify our findings in vitro. Results SS dose- and time-dependently induced liver injury in mice, indicated by increased serum AST, ALT and LDH levels. According to proteomic analysis, 487 differentially expressed proteins were identified in mice administrated with different dose of SS for different time periods. Altered proteins were enriched in pathways such as lipid metabolism, protein metabolism, macro molecular transportation, cytoskeleton structure and response to stress. SS enhanced CYP2E1 expression in a time and dose dependent manner, and induced oxidative stress both in vivo and in vitro. Conclusion Our results identified hepatotoxicity and established dose-time course-liver toxicity relationship in mice model of SS administration and suggested potential mechanisms, including impaired lipid and protein metabolism and oxidative stress. The current study provides experimental evidence for clinical safe use of RB, and also new insights into understanding the mechanism by which SS and RB induced liver injury

Generation of Broadband Emission by Incorporating N\u3csup\u3e3-\u3c/sup\u3e into Ca\u3csub\u3e3\u3c/sub\u3eSc\u3csub\u3e2\u3c/sub\u3eSi\u3csub\u3e3\u3c/sub\u3eO\u3csub\u3e12\u3c/sub\u3e:Ce\u3csup\u3e3+\u3c/sup\u3e Garnet for High Rendering White LEDs

Adding Si3N4 into green emitting Ca3Sc2Si3O12:Ce3+ garnet phosphor generates an additionally red emission band peaking around 610 nm that are assigned to Ce3+ ions having N3− in their local coordination. The excitation spectrum of the red band consists of not only a distinct band at 510 nm of itself but also an intense blue band at 450 nm that belongs to the typical Ce3+ ions with green emission, indicating a notable energy transfer from the green emitting Ce3+ ions to the red ones. The energy transfer significantly enables the achievement of a broad emission spectrum covering a red and green spectral region suitable for generating white light upon a blue light-emitting diode (LED) excitation. The decay patterns of the red and green fluorescence are discussed in relation to the effect of energy transfer. A white LED with high color rendering of 86 and low correlated color temperature of 4700 K is fabricated using the present single garnet phosphor

Low Friction at the Nanoscale of Hydrogenated Fullerene-Like Carbon Films

Friction force microscopy experiments at the nanometer scale are applied to study low friction of hydrogenated fullerene-like carbon films. The measured friction coefficients indicate that lower hydrogen concentration during preparation is beneficial to enter the low friction regime, especially in combination with only methane as precursor. Furthermore, two regions are found with distinct friction coefficients and surface roughnesses related to different surface structures. One is rich in amorphous carbon and the other is rich in fullerene-like carbon, dispersed on the same surface. Transmission electron microscopy and Raman spectroscopy images verify this observation of the two separated structures, especially with the extracted fullerene-like structures in the wear debris from macro friction experiments. It is speculated that hydrogen may tend to impair the growth of fullerene-like carbon and is therefore detrimental for lubricity

Molecularly imprinted electrochemical sensor based on electrode modified by functionalized carbon nanotube for selective detection of uric acid

1151-1158In this study, we have developed a novel biomimetic electrochemical sensor sensitized with functionalized carbon nanotubes using a molecularly imprinted film as a recognition element for the rapid detection of uric acid. Using K3[Fe(CN)6] as a probe, uric acid imprinted films on electrodes are characterized by voltammetry measurements and electrochemical impedance spectroscopy. The optimizations of experimental steps are conducted by cyclic voltammetry and differential pulse voltammetry. When the imprinted sensor is immersed in the solution containing a certain concentration of uric acid and incubated for a period of time, the oxidation peak current of K3[Fe(CN)6] decreases with the increase of uric acid concentration. Under optimal conditions, the peak current of K3[Fe(CN)6] has a good linear relationship with uric acid concentration at range from 0.1 μM to 3.3 μM with the detection limit of 0.03 μM. The proposed sensor shows high selectivity for rapid detection of uric acid in human serum samples

Research on the interface properties of geogrid with different mesh sizes

Due to its special mesh structure, geogrid can be embedded in the surrounding soil so effectively that the effects of reinforcement are comparatively better the other geotechnical composite materials. Geogrid has been adopted more and more widely in steep embankment reinforcement engineering. In practical engineering, the design of a reinforced body of soil with geogrid is usually based on Finite Elemental Method (FEM) numerical methods and calculation is carried out as a two-dimensional plane strain problem. This simplifies the geogrid with mesh structure into a single strip. The plausibility of calculating the strength indexes of the interface through interface parameters without considering the influence of the mesh size of the geogrid on the features of the interface should be studied. The current research on the interface properties of geogrid with different mesh sizes does not examine this issue thoroughly. By using large-sized shear experiments and FEM numerical methods, this paper studies the influences of the mesh size of geogrid on interface properties. The influence of mesh size on the features of the interface with geogrid can be displayed directly and quantitatively. This shows that larger mesh sizes result in higher strength indexes of the interface and a clearer reinforcement effect. The corresponding requirements of the geogrid material also increase; otherwise, the tensile strength would not be satisfied. The research results provide effective guarantees for the construction and operation of steep embankment reinforcement engineering, which is meaningful for safety engineering

Shrubland biomass and root-shoot allocation along a climate gradient in China

Background – Shrublands are receiving increasing attention because of climate change. However, knowledge about biomass allocation of shrublands at the community level and how this is regulated by climate is of limited availability but critical for accurately estimating carbon stocks and predicting global carbon cycles. Methods – We sampled 50 typical shrublands along a climate gradient in China and investigated the biomass allocation of shrubland at the community level and the effect of climate on biomass allocation. Shrub biomass was estimated using species-specific allometric relationships and the biomass of understory herbs was collected by excavating the whole plant. Regression analysis was used to examine the relationships between the biomass and the climate factors. RMA were conducted to establish the allometric relationships between the root and the shoot biomass at the community level.Key results – Shoot, root, and total biomass of shrub communities across different sites were estimated with median values of 206.5, 145.8, and 344.5 g/m2, respectively. Shoot, root, and total biomass of herb communities were estimated at 68.2, 58.9, and 117.2 g/m2, respectively. The median value of the R/S ratio of shrub communities was 0.58 and that of herb communities was 0.84. The R/S ratio of the shrub community showed a negative relationship with mean annual temperature and mean annual precipitation and a positive relationship with total annual sunshine and the aridity index. The R/S ratio of the herb community however showed a weak relationship with climate factors. Shoot biomass of the shrub community was nearly proportional to root biomass with a scaling exponent of 1.17, whereas shoot biomass of the herb community was disproportional to root biomass with a scaling exponent of 2.1.Conclusions – In shrublands, root biomass was more affected than shoot biomass by climate factors and this is related to water availability as a result of biomass allocation change of the shrub community. The understory herb community was less affected by climate due to the modification of the overstory–understory interaction to the climate-induced biomass allocation pattern. Shoot biomass of shrubs scales isometrically with root biomass at the community level, which supports the isometric theory of above-ground and below-ground biomass partitioning

Field aging declines the regulatory effects of biochar on cadmium uptake by pepper in the soil

Biochar application is not only being widely promoted as an ideal strategy to mitigate global climate warming, but it also has the advantage of reducing heavy metal bioavailability and migration in the soil. However, studies on the effects of field aging on biochar to reduce heavy metals from the soil are still limited. The present study aimed to explore the effects and mechanisms of aged biochar added to the soil planted with pepper plants on cadmium (Cd) uptake. To achieve this, un-amended soil (control), soil amended with fresh biochar, and aged biochar (biochar recovered from a long-term field trial after 9 years) were used to investigate the effects of field aging on biochar adsorption efficiency. The results revealed that the amount of Cd in the plant planted in control soil, amended with fresh and aged biochar, accounted for 40 ± 6.10, 17.18 ± 1.19, and 18.68 ± 0.79, respectively. There was a significant difference (P < 0.05) in the amount of Cd that was uptaken by plants among all treatments. However, soil amended with fresh biochar significantly (P < 0.05) decreased the amount of Cd in plants compared with soil amended with aged biochar. This indicates that field aging declines the potential of biochar to lower heavy metal bioavailability and retention in the soil. This study demonstrates that long-term burial lessens the ability of biochar to interact with Cd and suggests that biochar amendment can lower Cd in the soil, depending on the freshness and aging of biochar