Agricultural land-use change and rotation system exert considerable influences on the soil antibiotic resistome in Lake Tai Basin.

In this study, we use high-throughput quantitative polymerase chain reaction approaches to comprehensively assess the effects of agricultural land-use change on the antibiotic resistome of agricultural runoffs after rainfalls in Lake Tai Basin. For the first time in this region, our findings show that orchard runoffs harbored more diverse and abundant antibiotic resistance genes (ARGs) than traditional cropland runoffs. Network analysis demonstrated that orchard runoffs possessed a strong ability for ARG dissemination via horizontal gene transfer. These results suggest that residents might be exposed to a higher public health threat than before. Moreover, the present study confirmed that the rice-wheat rotation system plays a key role in regulating the soil antibiotic resistome profile. Using 16S rRNA high-throughput sequencing technology, this study clarified the relationships between the antibiotic resistome and soil microbiome composition. Finally, we discuss the key environmental factors driving changes in the soil antibiotic resistome. In summary, this study gives insight into the dissemination of environmental ARGs to the people living in the Lake Tai Basin.

In situ characterization of change in superficial organic components of thermoacidophilic archaeon Acidianus manzaensis YN-25.

For the first time, synchrotron radiation (SR) -based carbon K-edge X-ray absorption near edge structure (XANES) spectroscopy in-situ characterization was conducted to evaluate the evolution of superficial (about 10 nm) organic components of extracellular polymeric substances (EPS) of thermoacidophilic archaeon Acidianus manzaensis YN-25 acclimated with different energy substrates (FeS2, CuFeS2, S0, FeSO4). The atomic force microscopy (AFM) morphology scanning showed that the strain acclimated with different energy substrates varied a lot in EPS amount. XANES results showed clear associations between the energy substrates and the changes in organic composition in terms of typical function groups (CO, CO and CN). The chalcopyrite- and pyrite-acclimated cells contained higher proportion of proteins but less proportion of polysaccharides than the S0-acclimated cells. The FeSO4-acclimated cells contained the highest proportion of proteins, while the S0-acclimated cells contained more lipids and polysaccharides. The results of linear-combination and peak fitting of the K-edge XANES for the extracellular superficial organic component C is consistent with the trend in comparison with the results of FTIR and spectrophotometric determination, but there are significant differences in the values. These differences are caused by the inconsistencies of measurement depth between XANES and the latter two characterization methods.

Complete Genome Sequence of the Extremely Thermoacidophilic Archaeon Acidianus manzaensis YN-25.

The complete genome of Acidianus manzaensis YN-25 consists of a chromosome of 2,687,463 bp, with a G+C content of 30.62% and 2,746 coding DNA sequences. This archaeon contains a series of specific genes involved in the oxidation of elemental sulfur and reduced inorganic sulfur compounds.

[Clinical study on negative pressure closed drainage combined with vancomycin loaded calcium sulfate and autogenous bone in the treatment of chronic osteomyelitis].

OBJECTIVE: To study the clinical effects of negative pressure closed drainage combined with vancomycin loaded calcium sulfate and autogenous bone in the treatment of chronic osteomyelitis. METHODS: From June 2013 to December 2016, there were 35 cases of chronic osteomyelitis patients in our department, including 23 males and 12 females, ranging in age from 11 to 65 years old, with an average of 34 years old. The course of disease ranged from 8 to 46 months, with an average of 26 months. All patients were chronic osteomyelitis caused by open wounds. The lesions had recurrent redness and swelling and purulent skin perforation. Thirty-two patients had positive results in bacterial culture of sinus secretions, and 3 patients had negative results. Imaging examination showed the lesions of bone destruction, bone defects, surrounded by bone hyperplasia sclerosis. At the first stage, complete debridement was performed to remove necrotic tissues and inflammatory tissues; and the dressing of negative pressure closed drainage was used to completely cover the wound so as to promote the repair of the wound. At the second stage, the vancomycin loaded, calcium sulfate and autogenous iliac cancellous bone were mixed into the bone graft complex to evenly fill the lesions. The healing of the wound was observed and X-ray examination of the lesion was carried out to observe the absorption of calcium sulfate and the growth of new bone. RESULTS: Twenty-six patients underwent debridement and negative pressure closed drainage on time, 6 patients 2 times, and 3 patients 3 times. Thirty-two patients had incisions healed with grade A; 2 patients had incisions healed with grade B, and got completely healing after anti-infection, and wound dressing treatment; 1 patient had an incision healed with grade C, and got normal healing after re-debridement at the 4th week after operation. All patients did not have skin redness and ulceration again. X-ray imaging showed that the implanted calcium sulphate was absorbed gradually around 4 weeks, new bone was formed at 8 weeks, and bone defects in the lesions area were healed completely at 6 months to 2 years. CONCLUSIONS: Negative pressure closed drainage combined with vancomycin loaded calcium sulfate and autogenous bone in the treatment of chronic osteomyelitis is a good and reliable method, worthy of clinical promotion.

Fabrication of Ag-Nanorods/Polyimide Nanocomposites and Their Thermal, Mechanical, Electrical, and Dielectric Properties.

Silver nanorods/polyimide (Ag-NRs/PI) nanocomposites with high conductivity (An order of magnitude higher than pure PI), frequency-independent dielectric permittivity (3.8-4.2) and low dielectric loss (<0.05) were prepared by an in-situ polymerization process. Ag-nanorods with a mean width of approximately 300 nm and an average length over 8 microm were synthesized in the presence of polyvinylpyrrolidone (PVP) and NaCl by polyol process. SEM images showed that metallic Ag-nanorods were well dispersed in PI matrix. The structure of Ag-NRs was not destroyed or changed in nanocomposite films and the order of PI molecular chains was maintained as well. The orientation of the Ag-NRs in the PI matrix improved the mechanical properties of nanocomposite films. TGA results showed that the thermal property of nanocomposite films was almost as good as pure PI.

[Quantitative detection of hydroxyl radical generated in quartz powder/phosphate buffer solution system by fluorescence spectrophotometry].

Quartz powder would release radical hydroxyl in phosphate buffer solution. In order to detect the quantity of radical hydroxyl with a quite low concentration, the present paper established a fluorescence method. According to the relationship between the concentration of 2-hydroxyl of terephthalic acid (HOTP) and fluorescence intensity at the wavelength of EX(max)/EM(max) = 316 nm/422 nm, a working standard curve was constructed. Then through the filtrated fluorescence intensity obtained from the powder and solution system, cumulative concentration of * OH can be measured indirectly. By repeating tests and analysis of five different experimental conditions of * OH cumulative concentration, the minimum detection limit of the method reached 1.59 x 10(-10) mol x L(-1), with a relative deviation of 1.20%-7.89%, standard deviation was 1.09 x 10(-9)-2.17 x 10(-9) mol x L(-1) and the relative standard deviation was 3.5%-5.8%. The method features high accuracy and good repeatability performance. Compared to other quantitative studies, this method might be applied to test radical hydroxy produced in pH neutral solution systems. In addition, it has apparent advantages such as low detection limit, low cost, higher sensitivity, and better stability and reproducibility. That provides the means for the quantitative study of mixed systems consisting of quartz powder and phosphate buffered solution.

[Effect of burn blister fluid on human mesenchymal stem cell (MSC) in vitro and its phenotypic modulation in culture].

OBJECTIVE: To study the effect of blister fluid obtained from burn patient on human MSCs in vitro and its phenotypic modulation in culture. METHODS: Blister fluid from burn patients was collected at 12, 24, 48 post burn hour (PBH). The human MSCs were isolated, cultured, amplified and identified in vitro, then were divided into A (culture with 20% blister fluid collected at 12 PBH) , B (culture with 20% blister fluid collected at 24 PBH), C (culture with 20% blister fluid collected at 48 PBH), N (with ordinary culture medium) groups. The growth of MSCs and micro-organisms in blister fluid were observed. Positive expression rates of CD44 and CK7 were detected by flow cytometry after culture for 8 days. RESULTS: Bacterial and fungal growths were absent in 15 blister fluid samples. There was no obvious change in MSC morphology in each group. Compared with that of N group, the number of MSCs in A, B, C groups was decreased, especially in C group. CD44 positive expression rate in A, B, C groups was (83.0 +/- 3.1)%, (77.2 +/- 2.9)% and (65.1 +/- 2.3)%, respectively,which was obviously lower than that in N group [(89.5 +/- 3.2)%, P < 0.01]. CK7 positive expression rate in A, B, C groups was (24.06 +/- 0.11)%, (16.41 +/- 0.09)% and (4.48 +/- 0.07)%, respectively, which was obviously higher than that in N group [(3.87 +/- 0.04)%, P < 0.01]. CONCLUSIONS: Burn blister fluid can obviously inhibit the growth of human MSC cultured in vitro, and may promote modulation of its phenotype to certain extent.

[Distribution and drug resistance analysis of bacteria in different wound infections].

OBJECTIVE: To analyze the distribution and drug resistance of bacteria in different wound infections and provide evidence for wound infection control in subtropical regions. METHODS: This study involved 265 patients from 4 different departments of our hospital who experienced wound infections between July, 2007 and July, 2008. The bacterial strain distribution in the wounds and drug resistance of the bacteria were analyzed. RESULTS: Acinetobacter baumanii (39% of the total strain identified) was the most frequent bacterial strain causing infection of the burn wounds, followed by Proteus mirabilis (20%) and Pseudomonas aeruginosa (20%). E. coli infection was prevalent in the departments of general surgery (37%) and urinary surgery (64%), and Pseudomonas aeruginosa and Pseudomonas pneumonia infections were detected at the rate of 30% and 43% in the urinary surgery department, respectively. Different bacterial strains were found at similar rates around 10% in the wounds of patients undergoing traumatic surgery. CONCLUSION: Despite that the commonly seen pathogenic bacteria in burn patients including Staphylococcus aureus have been effectively controlled by early application of antibiotics, the opportunistic pathogens such as Acinetobacter baumanii and Proteus mirabilis often survive these antibiotics, and some strains evolve to be drug-resistant and even multi-drug-resistant. E. coli infection is prevalent in general surgery and urinary surgery departments, where Staphylococcus aureus and Pseudomonas aeruginosa infections can also be found frequently. All kinds of bacteria infection are present in trauma surgery department, each found at the rate around 10%.