The superlarge Dongfeng gold deposit is located in the Potouqing faults-alteration belt of the eastern part of the 'Zhao-Lai-gold ore belt', which belongs to the northwestern part of the Jiaodong area. Tectonically, ore bodies are controlled by faults and gold mainly occurs in the pyrite and polymetallic sulfide-bearing quartz vein. In this paper, Rb-Sr isotopic analysis is carried out with the beresite, which formed by hydrothermal metasomatism, and the Rb-Sr isochron age is 125.5±6.7Ma, indicating this deposit set up in the early Cretaceous of the late Yanshanian. Based on the relationship between the Dongfeng gold deposit and the Mesozoic granite, it is suggested that the formation of the gold deposit is a complex geological process of gradual enrichment and precipitation of the ore-forming elements. The initial 87Sr/86Sr ratio of the beresite is 0.711502±0.000069, which indicates the ore-forming materials mainly come from the crust. Combined with the complex mineralization process of the Dongfeng gold deposit and the reported H-O isotopic data, it is suggested that the ore-forming materials are mainly derived from the crust with some mantle materials, while the ore-forming fluids are originated primarily from magmatic hydrothermal and mantle with some precipitate water.

ABSTRACT Housefly, Musca domestica, has a complicated immune system. However, its underlying operating mechanism remains elusive. Candida albicans is a major pathogen affecting humans by causing deep infection fungous disease, but it is non-symbiotic in houseflies. To investigate the C. albicans infection process in housefly, the changes in morphological and histological and expression patterns of antimicrobial peptide were monitored to indicate the insect's response to fungal infection. The results showed that scattered brown spots were comprising melanized encapsulation and encapsulated fungal cells were initially observed at the inner side of larvae's body wall 3 h post-infection (PI). Between 6 and 36 h PI, the whole body of larvae was densely covered with the brown spots, which then gradually disappeared. The majority had disappeared at 48 h PI. Some fungi colonized in the gaps between the body wall and the muscle layer, as well as among muscle fibers of the muscle layer at 12 h PI and hyphal was observed at 18 h PI. These fungi colonized distribution changed from a continuous line to scattered spots at 24 h PI and virtually disappeared at 48 h. The results of quantitative PCR analysis revealed that in coordination with the variation during the infection, the expression levels of four antimicrobial peptides were up-regulated. In conclusion, C. albicans infection in M. domestica larvae involved the following stages: injection, infection, immune response and elimination of the pathogen. The rapid response of antimicrobial peptides, melanized encapsulation and agglutination played a vital role against the pathogenic invasion.