Nano-sized metal oxides are currently the most manufactured nanomaterials (NMs), and are increasingly used in consumer products. Recent exposure data reveal a genuine potential for adverse health outcomes for a vast array of NMs, however the underlying mechanisms are not fully understood. To elucidate size-related molecular effects, differentiated THP-1 cells were exposed to nano-sized materials (n-TiO2, n-ZnO and n-Ag), or their bulk-sized (b-ZnO and b-TiO2) or ionic (i-Ag) counterparts, and genome-wide gene expression changes were studied at low-toxic concentrations (<15% cytotoxicity). TiO2 materials were nontoxic in MTT assay, inducing only minor transcriptional changes. ZnO and Ag elicited dose-dependent cytotoxicity, wherein ionic and particulate effects were synergistic with respect to n-ZnO-induced cytotoxicity. In gene expression analyzes, 6 h and 24 h samples formed two separate hierarchical clusters. N-ZnO and n-Ag shared only 3.1% and 24.6% differentially expressed genes (DEGs) when compared to corresponding control. All particles, except TiO2, activated various metallothioneins. At 6 h, n-Zn, b-Zn and n-Ag induced various immunity related genes associating to pattern recognition (including toll-like receptor), macrophage maturation, inflammatory response (TNF and IL-1beta), chemotaxis (CXCL8) and leucocyte migration (CXCL2-3 and CXCL14). After 24 h exposure, especially n-Ag induced the expression of genes related to virus recognition and type I interferon responses. These results strongly suggest that in addition to ionic effects mediated by metallothioneins, n-Zn and n-Ag induce expression of genes involved in several innate and adaptive immunity associated pathways, which are known to play crucial role in immuno-regulation. This raises the concern of safe use of metal oxide and metal nanoparticle products, and their biological effects.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Two novel phenyl esters and partial phenyl esters of (dicloromethylene)bisphosphonic acid were synthesised. Three new layered Cd complexes of (dichloromethylene)bisphosphonic acidP,P-diphenyl, monophenyl and monoethyl esters were prepared. The complexes, [Cd3{(Cl2CP2O6Ph)2(H3COH)(H2O)5}(H2O)2]n (7), [{Cd(Cl2CP2O6Ph2)(H2O)3}(H2O)]n (8) and [{Cd1.5(Cl2CP2O6Et)(H2O)2}(C3H6O)0.5(H2O)4.5]n (9), were characterized by single crystal X-ray diffraction, IR spectroscopy, solid-state 31P- and 113Cd-CP/MAS NMR and elemental analysis. Also their thermal behaviour was investigated. Compound 7 consists of 1D chains with four independent octahedral Cd atoms joined by two L1 ligands, L1 = (Cl2CP2O6Ph)3−. The chains are connected into layers by phosphonate O atoms, and the adjacent layers are held together by face-to-face π–π stacking interactions. Compound 8 shows a new type of layered structure for metal bisphosphonates, where the L2 ligand, L2 = (Cl2CP2O6Ph2)2−, coordinates tridentately to three Cd2+ ions. Each CdO6 octahedron is connected to three CPO3 tetrahedra and each tetrahedron to three octahedra leading to a 2-D framework consisting of 12-membered cyclic cores. The layers are held together by edge-to-face CH/π interactions. In compound 9, the asymmetric unit contains two independent Cd2+ cations connected by L3 ligands, L3 = (Cl2CP2O6Et)3– and aqua ligands, to form a Cd–bisphosphonate layer. The layers are further interconnected into a 3-D supramolecular network by extensive hydrogen bonds.
Defect spinel phase lithium titanate (Li 4 Ti 5 O 12 ) has been suggested as a promising negative electrode material for next generation lithium ion batteries. However, it suffers from low electrical conductivity. To overcome this problem conduction path length can be reduced by decreasing the primary particle size. Alternatively the bulk conductivity of Li 4 Ti 5 O 12 can be increased by doping it with a conductive additive. In this paper a steady, single-step gas-phase technique for lithium titanate synthesis that combines both approaches is described. The process is used to produce doped Li 4 Ti 5 O 12 nanoparticles with primary particle size of only 10 nm. The product is found to consist of single-crystalline nanoparticles with high phase and elemental purity. Two dopant materials are tested and found to behave very differently. The silver dopant forms a separate phase of nanometre-sized particles of metallic silver which agglomerate with Li 4 Ti 5 O 12 . The copper dopant, on the other hand, reacts with the lithium titanate to form a double spinel phase of Li3(Li1−2xCu3xTi5−x)O12.
Equipment consisting of annular denuders, a filter, and a polyurethane foam adsorbent was used for sampling 15 PAHs from the diluted emission from a heat-storing masonry heater. The denuder method was compared to the ISO 11338 method which was used for the sampling from hot and undiluted exhaust gas. The denuder method used with the exhaust dilution gave a realistic gas–particle distribution of PAHs in more atmospheric-like conditions compared to the sampling from undiluted exhaust gas where PAHs were almost totally in the gas phase. The results gained with the denuder method from the diluted exhaust are more relevant, e.g., from exposure and atmospheric processes point of view. The emissions from smoldering combustion conditions (SC) were compared with the emissions from normal combustion conditions (NC). The emission of each PAH was 7 to 14 times higher from SC than from NC, and the gas–particle distribution was shifted towards the particle phase due to increased condensation of PAHs. The PAHs could be divided into three groups based on their phase distributions. In the first group, PAHs existed mostly in the gas phase in both combustion cases; the vapor pressures of PAHs were lower than the saturation vapor pressures. In the second group, the gas phase was saturated and the concentration was almost the same in both combustion cases, whereas the particle phase concentration was higher in SC. In the third group, PAHs were mostly in the particle phase where the concentration was higher in SC.
