Removal of sulfamethoxazole and antibiotic resistance genes in paddy soil by earthworms (Pheretima guillelmi): Intestinal detoxification and stimulation of indigenous soil bacteria.

Vermiremediation, which use earthworms to remove contaminants from soil, has been proven to be an alternative, low-cost technology. However, the effects of earthworm activity, especially the degraders in earthworm intestines, on the fate of sulfamethoxazole (SMX), and the effects of intestinal bacteria on degrading bacteria in soil are unclear. In this study, the effects of earthworms on the fate of SMX and related antibiotic resistance genes (ARGs) were investigated. Special attention was paid to the impact of earthworms on SMX degradation efficiency, degradation products, related ARGs, and degraders in both soil and earthworm intestines; the effect of intestinal bacteria on soil bacteria associated with SMX was also studied. Earthworms significantly accelerated SMX degradation by both intestinal detoxification and the stimulation of indigenous soil bacteria. Compared with the treatment without earthworms, the treatment with earthworms reduced SMX residues by 25.1 %, 49.2 %, 35.7 %, 34.2 %, and 35.7 % on the 10th, 20th, 30th, 60th, and 90th days, respectively. Compared with those in soil (treated with earthworms), the SMX residues in wormcasts were further reduced by 12.2-29.0 % from the 2nd to the 20th day, producing some unique anaerobic degradation products that were distinct from those in the soil. In earthworm intestines, SMX degradation was enhanced by bacteria of the genera Microvirga, Sphingomonas, Methylobacterium, Bacillus, and Tumebacillus. All of these bacteria (except Bacillus spp.) entered and colonised the soil with wormcasts, further promoting SMX degradation. Additionally, earthworms removed a significant number of ARGs by increasing the fraction of potential SMX degraders and inhibiting the potential hosts of ARGs and int1. This study demonstrated that earthworms could remediate SMX-contaminated soil by enhancing the removal of SMX and ARGs.

Carbon-Phosphorus Coupling Governs Microbial Effects on Nutrient Acquisition Strategies by Four Crops.

Plants adjust root morphological and/or exudation traits in response to phosphorus (P) mobilization mediated by microorganisms. We hypothesized that straw application coupled with P fertilization would influence microbial P and then root nutrient-acquisition strategies related to crop growth. Root morphological (length and average diameter) and exudation traits (acid phosphatase and carboxylates) of Brassica chinensis, Solanum lycopersicum, Lactuca sativa, and Vigna unguiculata in response to microbial P dynamics were characterized in no-P and P-fertilized soil with/without straw addition. Straw addition increased the growth of fungi and bacteria, stimulating microbial P immobilization at day 24. The high microbial abundance was associated with four tested crops having short roots in straw-amended compared with no-straw soil at day 24. In straw-amended soil, B. chinensis and S. lycopersicum shifted toward root P-acquisition strategies based on fast elongation and strong carboxylate exudation from days 24 to 40. Such effective root P-acquisition strategies together with microbial P release increased shoot P content in S. lycopersicum in straw-amended compared with those without straw at day 40. Conversely, L. sativa and V. unguiculata produced short roots in response to the stable (or even increased) microbial P after straw addition till day 40. In straw-amended soil, high P application stimulated root elongation and carboxylate exudation in L. sativa and V. unguiculata, whereas carboxylate exudation by S. lycopersicum was decreased compared with the straw-amended but non-fertilized treatment at day 40. In summary, root P-acquisition strategies in response to microbial P differed among the tested crop species. Phosphorus fertilization needs to be highlighted when returning straw to enhance P-use efficiency in vegetable cropping systems.

A novel electrochemical sandwich-like immunosensor based on carboxyl Ti3C2Tx MXene and rhodamine b/gold/reduced graphene oxide for Listeria monocytogenes.

Listeria monocytogenes (LM) is one of the most common food-borne pathogens and can induce a series of diseases with a high mortality rate to humans; hence, it is very necessary to develop a highly sensitive method for LM detection. Based on this need, a new sandwich-like electrochemical immunosensing platform was developed herein by preparing carboxyl Ti3C2Tx MXene (C-Ti3C2Tx MXene) as the sensing platform and rhodamine b/gold/reduced graphene oxide (RhB/Au/RGO) as the signal amplifier. The high conductivity and large surface area of C-Ti3C2Tx MXene make it a desirable nanomaterial to fix the primary antibody of LM (PAb), while the prepared Au/RGO/RhB nanohybrid is dedicated to assembling the secondary antibody (SAb) of LM, offering an amplified response signal. Through the use of RhB molecule as the signal probe, the experiments showed that the peak currents of RhB increase along with an increase in the concentration of LM from 10 to 105 CFU mL-1, and an extremely low limit of detection (2 CFU mL-1) was obtained on the basis of the proposed immunosensing platform after optimizing various conditions. Hence, it is confirmed that the developed sandwich-like immunosensor based on C-Ti3C2Tx MXene and RhB/Au/Gr has great application in the detection of LM and other analytes.

Effects of long-term integrated agri-aquaculture on the soil fungal community structure and function in vegetable fields.

The diversity and community structure of soil fungi play an important role in crop production and ecosystem balance, especially in paddy-upland vegetable field systems. High-throughput sequencing was used to study changes in the soil fungal community structure and function in paddy-upland vegetable field systems. The results showed that compared with traditional planting, the diversity and community structure of soil fungi were changed by the combination of flooding and drought, the Shannon index increased by 11.07%, and the proportion of the dominant species, Mortierella, decreased by 22.74%. Soil available nitrogen, total phosphorus, available phosphorus, total nitrogen and organic matter played a leading role in the initial stage of the experiment, while the dominant factor changed to total potassium 3 years later and then to soil pH and water content 6 years later. FUNGuild analysis showed that the proportion of three independent trophic modes of soil fungi were increased by the combined flooded-drought model, and there were multiple interaction factors, For example, nutrient supply, pH and planting pattern. This study showed that soil fertility, crop yield and economic benefits were better than the traditional model after three years of planting and breeding. The longer the time, the better the effect.

Effect of nitrogen application rate on soil fungi community structure in a rice-fish mutualistic system.

Rice-fish mutualistic production systems rationalise the use of water and soil resources in an improved approach to sustainable food production. However, drivers of fungi community structure in paddy soil, including effects of nitrogen (N) application rate, are unclear in these systems. Here, we assessed soil fungi community and soil physicochemical responses in paddy soil to contrasting rates of N application in a rice-fish system. To clarify the mutualistic effects, the rice-fish system was compared with a standard rice monoculture under a 325.5 kg ha-1 N application rate. The results showed that N application rate affected abundance of paddy soil fungi (P < 0.05). Alpha diversity and richness of fungi were lower in the rice-fish system, but evenness increased with a decrease in N application rate, while the rate of N determined diversity of soil fungi in the rice-fish system. Dominant genera in the two systems differed, and soil physicochemical properties were more important drivers of soil fungi community structure in the rice-fish mutualistic system than in rice monoculture. Total N, available N and P regulated the abundance of dominant fungi. Our results indicate that management of soil fungi may contribute to sustainable agricultural production.

Increased planting density of Chinese milk vetch (Astragalus sinicus) weakens phosphorus uptake advantage by rapeseed (Brassica napus) in a mixed cropping system.

Neighbouring plants can affect plant growth through altering root morphological and physiological traits, but how exactly root systems respond to neighbouring plants with varied density, determining nutrient uptake and shoot growth is poorly understood. In a pot-based experiment, rapeseed was grown alone (single rapeseed), or mixed with 3, 6, or 15 Chinese milk vetch plants. As controls, monocropped Chinese milk vetch was grown at the same planting density, 3, 6, or 15 plants per pot. Root interaction between rapeseed and Chinese milk vetch facilitated phosphorus (P) uptake in rapeseed grown with 3 plants of Chinese milk vetch. As the planting density of Chinese milk vetch in mixture increased, there was a decrease in citrate concentration and acid phosphatase activity but an increase in the total root length of Chinese milk vetch per pot, resulting in decreases in rapeseed root biomass, total root length and P uptake when rapeseed was grown with 6 or 15 Chinese milk vetch plants relative to rapeseed grown with 3 plants. These results demonstrate that the enhanced nutrient utilization induced by root interaction at low planting densities was eliminated by the increased planting density of the legume species in rapeseed/Chinese milk vetch mixed cropping system, suggesting that root/rhizosphere management through optimizing legume planting density is important for improving crop productivity and nutrient-use efficiency.

A systematic review of growth hormone for hip fractures.

OBJECTIVE: To evaluate the clinical effectiveness of growth hormone (GH) for hip fractures. DESIGN: Based on the principles and methods of Cochrane systematic reviews, we searched the Cochrane Library (2011, 3 issue), PubMed (1966 to October 2011), EMBASE (1974 to October 2011), OVID database (1963 to October 2011), Chinese Bio-medicine database (1978 to October 2011), China Journal Full-text Database (1979 to October 2011), and VIP database (1989 to October 2011). Randomized controlled trials (RCTs) of GH treatment for hip fractures were included. We assessed the quality of included trials according to the Cochrane Handbook for Systematic Reviews of Interventions Version. The Cochrane Collaboration's software RevMan 5.0 was used for meta-analysis. RESULTS: 3 RCTs with a total of 162 hip fractures patients were included. Results of GH compared to placebo treatment showed that IGF-I levels significantly increased in the short term, but no significant differences in the long term. Additionally, there was no statistical difference in adverse events. Only one trial reported the measurement of bone mineral content (BMC), which showed that GH group was unchanged while the placebo group lost BMC at both 4 weeks and 8 weeks. Only one study measuring BMC showed no significant differences in the change of the MBI scores between GH group and placebo group; however, the changes from baseline in the hGH group were less than that in the placebo group among the older than 75 years group. Owing to the difference of measurement indexes in those studies, we could not perform a meta-analysis. CONCLUSIONS: With the low quality of current evidence, GH may be effective in hip fractures. More carefully designed, double-blinded and placebo-controlled randomized trials with large numbers of participants about GH in the treatment of hip fractures are required.

[Anti-cervix-cancer effect of the co-immobilization of tumor necrosis factor-alpha and interferon-gamma].

To explore the effect of the co-photo-immobilization of Recombinant Human Interferon-r (IFN-gamma) and Recombinant Tumor Necrosis Factor (TNF-alpha) on the Hela cell cultivated in vitro. Co-immobilize the photoactive IFN-gamma and TNF-alpha on the polystyrene membrane; Cultivate the Hela cell on the cell culture polystyrene plate surface and set up the cultivation of the photo-immobilization IFN-gamma+TNF-alpha, Photo-immobilization IFN-gamma, nature (IFN-gamma, TNF-alpha, IFN-gamma+TNF-alpha). After 48 hours, the inhibition effect against Hela cells was studied in vitro by SEM and flow cytometry. It showed that the co-immobilization IFN-gamma+TNF-alpha has a more obvious inhibition effect on the Hela cell. And IFN-gamma can cooperate with TNF-alpha obviously.