No abstract

Replacement of primary old-growth forests by secondary woodlands in threatened subtropical biomes drives important changes at the level of the overstory, understory and forest floor, but the impact on belowground microbial biodiversity is yet poorly documented. In the present study, we surveyed by metabarcoding sequencing, the diversity and composition of soil bacteria and fungi in the old-growth forest, dominated by stone oaks (Lithocarpus spp.) and in the secondary Yunnan pine woodland of an iconic site for biodiversity research, the Ailaoshan National Nature Reserve (Ailao Mountains, Yunnan province, China). We assessed the effect of forest replacement and other environmental factors, including soil horizons, soil physicochemical characteristics and seasonality (monsoon vs. dry seasons). We showed that tree composition and variation in soil properties were major drivers for both bacterial and fungal communities, with a significant influence from seasonality. Ectomycorrhizal Operational Taxonomic Units (OTUs) dominated the functional fungal guilds. Species richness and diversity of the bacterial and fungal communities were higher in the pine woodland compared to the primary Lithocarpus forest, although prominent OTUs were different. The slightly lower complexity of the microbiome in the primary forest stands likely resulted from environmental filtering under relatively stable conditions over centuries, when compared to the secondary pine woodlands. In the old-growth forest, we found a higher number of species, but that communities were homogeneously distributed, whereas in the pine woodlands, there is a slightly lower number of species present but the communities are heterogeneously distributed. The present surveys of the bacterial and fungal diversity will serve as references in future studies aiming to assess the impact of the climate change on soil microbial diversity in both old-growth forests and secondary woodlands in Ailaoshan.

Gut bacterial communities play a crucial role in shrimp growth and health. However, these communities are still vulnerable to pressures (such as high temperatures) that hinder their functions. Here, shrimps were cultured for 6 weeks at three different temperatures: a variable temperature (control group, falling from 23.7 to 20.8°C with ambient temperature) and two fixed temperatures (26 and 30°C) to study their effects on growth, enzyme activity and gut microbes of shrimp. The results indicated that increasing temperature significantly decreased the survival rate of shrimp but had a significant rise in shrimp growth performances with the higher phosphatase enzyme activities than control group. Although the high temperature did not change the alpha diversity indexes of the bacterial communities, their compositions were significantly different, compared with that of control group. The relative abundances of the top 10 families showed a discrepancy in the dominance of the bacterial community, represented by Vibrionaceae and Mycoplasmataceae at 26 and 30°C groups, and Rhodobacteraceae and Flavobacteriaceae in the control group. These results indicate that temperature changes mainly affected the compositions of bacterial community, which increased the susceptibility of shrimp to some pathogenic bacterial species, such as Vibrio, thus leading to a low survival rate of shrimp.

The aim of the study was to investigate the efficiency and safety of zoledronic acid and ibandronate in the treatment of rats with lung cancer combined with bone metastases. A total of 124 rats with lung cancer bone metastasis were established. Rats were randomly divided into A, B and C groups (n=30). Rats in group A were treated with ibandronate combined with zoledronic acid, rats in group B were treated with zoledronic acid monotherapy, and rats in group C were treated with ibandronate monotherapy. Rats in group A were injected subcutaneously with zoledronic acid 0.1 mg/kg and ibandronate 10 µg/kg, once per week for 12 weeks; rats in group B were injected subcutaneously with zoledronic acid, and rats in group C were injected subcutaneously with ibandronate, the same method as the treatment group. The remaining 34 SD rats were not treated to serve as the control group. Treatment efficacy and physical improvement in 8 weeks were observed, and improvement of pain behavior in rats was evaluated to reflect the effect of drug treatment. Of the 30 rats in group A, 25 showed different degrees of remission, 5 rats showed no improvement and the effective rate was 83.3%. Of the 30 rats in group B, 21 showed different degrees of remission, 9 rats showed no improvement and the effective rate was 70%. Of the 30 rats in group C, 20 showed different degrees of remission, 10 rats showed no improvement and the effective rate was 66.7%. Statistically significant differences in total effective rate were found among three groups, and the combined method showed the highest effective rate (P<0.05). Ibandronate combined with zoledronic acid has a good therapeutic effect on cancer pain caused by bone metastases from lung cancer.