RESUMO
The use of magnetic biosorbents for the remediation of heavy metals has attracted increasing attention due to their ease of separation and reusability. We developed a method for preparing superparamagnetic biosorbent materials using water-based magnetic fluids. Water-based magnetic fluid-spores (WMFSs) were obtained by combining water-based magnetic fluid (WMF) with Aspergillus niger spores at ratios of 0.6:1 (WMFS1), 0.8:1 (WMFS2), 1:1 (WMFS3), 1.2:1 (WMFS4), and 1.4:1 (WMFS5). A magnetic composite material was prepared from magnetic nanoparticles and spores in a ratio of 1:1 as a control. The adsorption efficiency and separation effect of WMFS3 were significantly better than those of the magnetic composite material. The morphology and structure of WMFS3 were characterized by performing transmission electron microscopy. The results showed that Fe3O4 magnetic particles were uniformly coated on the spore surface. The superparamagnetism of WMFS3 was tested using a vibrating sample magnetometer. At pH 2.0, the maximum adsorption capacity of WMFS3 for Cr(VI) was 105 mg/g; in the pH range of 2.0-3.0, the adsorption equilibrium time of WMFS3 was 60 min. Thus, the adsorption process conformed to the pseudo-second-order kinetic model and Freundlich isotherm. Thermodynamic studies showed that the process was spontaneous and endothermic. The adsorption mechanisms of WMF3 for Cr(VI) included electrostatic, reduction, and complexation adsorption. This biosorbent material showed excellent adsorption performance for Cr(VI) and is promising for wastewater resource applications.
Assuntos
Poluentes Químicos da Água , Água , Adsorção , Aspergillus niger , Cromo/análise , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Esporos Fúngicos/química , Poluentes Químicos da Água/análiseRESUMO
The rapid development of terahertz technology promotes the realization of various terahertz imaging systems. Terahertz technology features terahertz waves as good non-invasive illumination sources due to their high spectral resolution, penetration and safety. The terahertz imaging technique (TIT) has gradually been extended from the biomedical field to the field of Chinese medicine (CM), and it has become a powerful tool for seeking scientific evidence for CM theories with the use of modern science and technology. This paper reviews the current application of TITs in the field of CM research, and most importantly offers novel proposals for the application of TITs in CM research from the perspective of CM syndrome objectification and acupuncture research and cites existing reports as reference to the feasibility of these new proposals.
Assuntos
Terapia por Acupuntura , Acupuntura , Moxibustão , Imagem Terahertz , Medicina Tradicional ChinesaRESUMO
Physalin B (PB), one of the major active steroidal constituents of Solanaceae Physalis plants, has a wide variety of biological activities. We found that PB significantly down-regulated ß-amyloid (Aß) secretion in N2a/APPsw cells. However, the underlying mechanisms are not well understood. In the current study, we investigated the changes in key enzymes involved in ß-amyloid precursor protein (APP) metabolism and other APP metabolites by treating N2a/APPsw cells with PB at different concentrations. The results indicated that PB reduced Aß secretion, which was caused by down-regulation of ß-secretase (BACE1) expression, as indicated at both the protein and mRNA levels. Further research revealed that PB regulated BACE1 expression by inducing the activation of forkhead box O1 (FoxO1) and inhibiting the phosphorylation of signal transducer and activator of transcription 3 (STAT3). In addition, the effect of PB on BACE1 expression and Aß secretion was reversed by treatment with FoxO1 siRNA and STAT3 antagonist S3I-201. In conclusion, these data demonstrated that PB can effectively down-regulate the expression of BACE1 to reduce Aßsecretion by activating the expression of FoxO1 and inhibiting the phosphorylation of STAT3.