Chromium (Cr) is the seventh most abundant chemical element in the Earth’s crust, and Cr(III) and Cr(VI) are common stable valence states of Cr. Several Cr-containing substances, such as FeOCr₂O₃ and stainless-steel products, exist in nature and in life. However, Cr(VI) is toxic to soil, microorganisms, and plants and poses a serious threat to human health through direct and indirect exposure. By collecting published journal literature, we found that Cr(VI) can cause acute and chronic toxicity in organisms and has carcinogenic effects, and the mechanisms causing these toxicity include endoplasmic reticulum stress, autophagy and apoptosis. However, the relationship between these mechanisms remains unclear. Many methods have been researched to purify chromium, but each of these methods has its own advantages and disadvantages. Therefore, this review summarizes the hazards of chromium and the mechanisms of chromium toxicity after entering cells and provides a number of methods for chromium contamination management, providing a direction for the next step in chromium toxicology and contamination decontamination research.

Context: Cisplatin-based chemotherapy was widely used in treating human malignancies. However, side effects and chemoresistance remains the major obstacle. Objective: To verify whether natural borneol (NB) can enhance cisplatin-induced glioma cell apoptosis and explore the mechanism. Materials and methods: Cytotoxicity of cisplatin and/or NB towards U251 and U87 cells were determined with the MTT assay. Cells were treated with 0.25–80 μg/mL cisplatin and/or 5–80 μM NB for 48 h. The effects of NB and/or cisplatin on apoptosis and cell cycle distribution were quantified by flow cytometric analysis. Protein expression was detected by western blotting. ROS generation was conducted by measuring and visualising an oxidation-sensitive fluorescein DCFH-DA. Results: NB synergistically enhanced the anticancer efficacy of cisplatin in human glioma cells. Co-treatment of 40 μg/mL NB and 40 μg/mL cisplatin significantly inhibited U251 cell viability from 100% to 28.2% and increased the sub-G1 population from 1.4% to 59.3%. Further detection revealed that NB enhanced cisplatin-induced apoptosis by activating caspases and triggering reactive oxygen species (ROS) overproduction as evidenced by the enhancement of green fluorescence intensity from 265% to 645%. ROS-mediated DNA damage was observed as reflected by the activation of ATM/ATR, p53 and histone. Moreover, MAPKs and PI3K/AKT pathways also contributed to co-treatment-induced U251 cell growth inhibition. ROS inhibition by antioxidants effectively improved MAPKs and PI3K/AKT functions and cell viability, indicating that NB enhanced cisplatin-induced cell growth in a ROS-dependent manner. Discussion and conclusions: Natural borneol had the potential to sensitise human glioma cells to cisplatin-induced apoptosis with potential application in the clinic.

Background: Singlet oxygen (¹O₂) has received considerable research attention in photodynamic therapy (PDT) due to its cytotoxic solid features. However, the inherent hypoxic state of the tumor microenvironment (TME) leads to the meager ¹O₂ quantum yield of inorganic PDT reagents, and their application in vivo remains elusive.

Financial returns of forest plantations are an important concern around the world. In this research, we focused on South China’s timber investments, collected data from the Pingxiang, Guangxi Province, China, which is the demonstration zone of Fast-growing and High-yielding Timber Plantation Base Construction Program and National Timber Strategic Storage and Production Bases Construction Program, and used capital budgeting analysis method and sensitivity analysis to compare different scenarios of planted forest management. The results showed that excluding land costs, (1) the financial returns of Eucalyptus forest managed by small business were excellent, having an IRR of 28% per year and a LEV of $7555 per ha, but it had a high risk with fluctuations of cost, timber price and timber yield; (2) the results for the Experimental Center of Tropical Forests indicate that the Eucalyptus forest and Castanopsis hystrix forest returns were greater than those for Cunninghamia lanceolata forest and Pinus massoniana forest, with having IRRs of 24%, 21%, 13% and 10% per year respectively. The mixed planted forest of Castanopsis hystrix × Eucalyptus and Castanopsis hystrix × Pinus massoniana had the features of high profits and low risks; (3) the forest farmers had lower levels of returns for Eucalyptus forest management in South China, but were still in the middle rank of global comparisons. This study gave a view of China’s timber investment and provided more options of improving the economic returns of planted forest management to both small businesses and forest farmers in South China.

Hyperglycemia is the main feature of diabetes and may increase the risk of vascular calcification (VC), which is an independent predictor for cardiovascular and cerebrovascular diseases (CCD). Selenium (Se) may decrease the risk of CCD, and previous studies confirmed that Se-containing protein from Se-enriched Spirulina platensis (Se-SP) exhibited novel antioxidant potential. However, the effect of Se-SP against VC has been not investigated. Herein, the protective effect and underlying mechanism of Se-SP against high glucose-induced calcification in mouse aortic vascular smooth muscle cells (MOVAS) were explored. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) results showed time-dependent uptake of Se-SP in MOVAS cells, which significantly inhibited high glucose-induced abnormal proliferation. Se-SP co-treatment also effectively attenuated high glucose-induced calcification of MOVAS cells, followed by decreased activity and expression of alkaline phosphatase (ALP). Further investigation revealed that Se-SP markedly prevented reactive oxygen species (ROS)-mediated DNA damage in glucose-treated MOVAS cells. ROS inhibition by glutathione (GSH) effectively inhibited high glucose-induced calcification, indicating that Se-SP could act as ROS inhibitor to inhibit high glucose-induced DNA damage and calcification. Moreover, Se-SP dramatically attenuated high glucose-induced dysfunction of mitogen-activated protein kinases (MAPKs) and phosphatidylinositol-3-kinase/AKT (PI3K/AKT) pathways. Se-SP after Se addition achieved enhanced potential in inhibiting high glucose-induced calcification, which validated that Se-SP as a new Se species could be a highly effective treatment for human CCD.

Introduction: Hexavalent chromium or Cr(VI) is essential to various industries, such as leather manufacturing and stainless steel production. Given that inevitable leakage from industries pollutes the soil and thereby affects the soil environment. Microbial communities could improve the quality of the soil. Abundant bacterial communities would significantly enhance the soil richness and resist external pressure, benefiting agriculture. But the pollution of heavy metal broke the balance and decrease the abundance of bacterial communities, which weak the self-adjust ability of soil. This study aimed to explore changes in the diversity of soil bacterial communities and to identify the influences of soil bacterial communities on enzymes in soil polluted by Cr(VI).Methods: The target soils were sampled quickly and aseptically. Their chromium content was detected through inductively coupled plasma-mass spectrometry, and bacterial microbiome communities were explored through MiSeq high-throughput sequencing. Then, the content of nitrite reductase and catalases were investigated through enzyme-linked immunosorbent assay (ELISA).Results: Chromium content in polluted soils was higher than that in the control soils at all depths. Sobs, Chao1, Ace, and Shannon diversity estimators in the control were higher, whereas Simpson's diversity estimators in the control soils were lower than those of contaminated samples at all depths. Contaminants affected the composition of the bacterial community. The soil microbial species were relatively single and inhomogeneous in the polluted soils. The bacterial phyla in polluted and controlled soils include Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria, which differ markedly in abundance.Discussion: The results of these observations provide insights into the ecotoxicological effects of Cr(VI) exposure to soil microorganisms. To sum up these results are critical for evaluating the stabilized state of microbial community structures, contributing to the assessment of the potential risk of metal accumulation in soils.