Antibiotic resistance genes and heavy metals in landfill: A review.

Landfill is reservoir containing antibiotic resistance genes (ARGs) that pose a threat to human life and health. Heavy metals impose lasting effects on ARGs. This review investigated and analyzed the distribution, composition, and abundance of heavy metals and ARGs in landfill. The abundance ranges of ARGs detected in refuse and leachate were similar. The composition of ARG varied with sampling depth in refuse. ARG in leachate varies with the distribution of ARG in the refuse. The ARG of sulI was associated with 11 metals (Co, Pb, Mn, Zn, Cu, Cr, Ni, Sb, As, Cd, and Al). The effects of the total metal concentration on ARG abundance were masked by many factors. Low heavy metal concentrations showed positive effects on ARG diffusion; conversely, high heavy metal concentrations showed negative effects. Organic matter had a selective pressure effect on microorganisms and could provide energy for the diffusion of ARGs. Complexes of heavy metals and organic matter were common in landfill. Therefore, the hypothesis was proposed that organic matter and heavy metals have combined effects on the horizontal gene transfer (HGT) of ARGs during landfill stabilization. This work provides a new basis to better understand the HGT of ARGs in landfill.

[Comparative analysis of chemical compositions of fruits of Perilla frutescens var. arguta and P. frutescens var. frutescens by pre-column derivatization with GC-MS].

The present study compared the appearance and chemical composition of fruits of Perilla frutescens var. arguta(PFA) and P. frutescens var. frutescens(PFF). VHX-6000 3 D depth of field synthesis technology was applied for the appearance observation. The metabolites were qualitatively and quantitatively analyzed by pre-column derivatization combined with gas chromatography-mass spectrometry(GC-MS). Finally, cluster analysis(CA), principal component analysis(PCA), and orthogonal partial least-squares discriminant analysis(OPLS-DA) were applied for exploring the differences in their chemical compositions. The results indicated that the size and color of PFA and PFF fruits were different. PFF fruits were significantly larger than PFA fruits. The surface color of PFA fruits was brown, while PFF fruits were in multiple colors, such as white, grayish-white, and brown. Amino acids, saccharides, organic acids, fatty acids, and phenolic acids were identified in PFA and PFF fruits. The results of CA, PCA, and OPLS-DA indicated significant differences in the content of components between PFA and PFF fruits. Three metabolites, including D-glucose, rosmarinic acid, and D-fructose, which were significantly higher in PFA fruits than in PFF fruits, were screened out as differential metabolites. Considering the regulation on the content of rosmarinic acid in Perillae Fructus in the Chinese Pharmacopoeia(2020 edition), the medicinal value of PFA fruits is higher than that of PFF. In conclusion, there are differences in appearance and chemical composition between PFA fruits and PFF fruits. These results are expected to provide fundamental data for specifying plant source and quality control of Perillae Fructus.

Effects of intraoperative PEEP on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer: study protocol for a randomized controlled trial.

BACKGROUND: There are increasing studies showing that the use of a lung-protective ventilation strategy has a lung protection effect in patients undergoing abdominal surgery; however, the appropriate positive end-expiratory pressure (PEEP) has not yet defined. Adopting a suitable PEEP may prevent postoperative pulmonary complications. Robot-assisted laparoscopic surgery is the newest and most minimally invasive treatment for bladder cancer or prostate cancer. It is also necessary to consider the effects of Trendelenburg position with pneumoperitoneum on airway pressure and pulmonary function. The role of PEEP during the intraoperative period in preventing postoperative pulmonary complications for robot-assisted laparoscopic surgery is not clearly defined. METHODS/DESIGN: A total of 208 patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer will be enrolled and then randomly assigned to a standard PEEP (6-8 cm H2O) group and a low PEEP (≤2 cm H2O) group. Both groups will receive an inspired oxygen fraction of 0.50 and a tidal volume of 8 mL/kg ideal body weight. Standard perioperative fluid management standardization and analgesic treatments will be applied in both groups. The primary endpoint is postoperative pulmonary complications within 7 days after surgery. Secondary endpoints are the modified clinical pulmonary infection score, postoperative extrapulmonary complications, postoperative surgical complications, intensive care unit length of stay, hospital length of stay, and 30-day mortality. DISCUSSION: This trial aimed to assess the effects of low tidal volumes combined with intraoperative PEEP ventilation strategy on postoperative pulmonary complications in patients undergoing robot-assisted laparoscopic radical resection for bladder cancer or prostate cancer. TRIAL REGISTRATION: ID: ChiCTR1800019867 . Registered on December 2, 2018.

Source profiles and contributions of biofuel combustion for PM2.5, PM10 and their compositions, in a city influenced by biofuel stoves.

Source and ambient samples were collected in a city in China that uses considerable biofuel, to assess influence of biofuel combustion and other sources on particulate matter (PM). Profiles and size distribution of biofuel combustion were investigated. Higher levels in source profiles, a significant increase in heavy-biomass ambient and stronger correlations of K+, Cl-, OC and EC suggest that they can be tracers of biofuel combustion. And char-EC/soot-EC (8.5 for PM2.5 and 15.8 for PM10 of source samples) can also be used to distinguish it. In source samples, water-soluble organic carbon (WSOC) were approximately 28.0%-68.8% (PM2.5) and 27.2%-43.8% (PM10) of OC. For size distribution, biofuel combustion mainly produces smaller particles. OC1, OC2, EC1 and EC2 abundances showed two peaks with one below 1 µm and one above 2 µm. An advanced three-way factory analysis model was applied to quantify source contributions to ambient PM2.5 and PM10. Higher contributions of coal combustion, vehicular emission, nitrate and biofuel combustion occurred during the heavy-biomass period, and higher contributions of sulfate and crustal dust were observed during the light-biomass period. Mass and percentage contributions of biofuel combustion were significantly higher in heavy-biomass period. The biofuel combustion attributed above 45% of K+ and Cl-, above 30% of EC and about 20% of OC. In addition, through analysis of source profiles and contributions, they were consistently evident that biofuel combustion and crustal dust contributed more to cation than to anion, while sulfate & SOC and nitrate showed stronger influence on anion than on cation.

Anti-inflammatory Hydrolyzable Tannins from Myricaria bracteata.

Twelve hydrolyzable tannins were obtained from the twigs of Myricaria bracteata, including two new hellinoyl-type dimers, bracteatinins D1 (1) and D2 (2); a new hellinoyl-type trimer, bracteatinin T1 (3); two known monomers, nilotinin M4 (4) and 1,3-di-O-galloyl-4,6-O-(aS)-hexahydroxydiphenoyl-ß-d-glucose (5); six known dimers, tamarixinin A (6), nilotinin D8 (7), hirtellins A (10), B (9), and E (8), and isohirtellin C (11); and a known trimer, hirtellin T3 (12). The structures of the tannins were elucidated by spectroscopic data analysis and comparisons to known tannins. All compounds were evaluated as free radical scavengers using 1,1-diphenyl-2-picrylhydrazyl and hydroxy radicals and compared to the activity of BHT and Trolox. Compound 6 showed a significant anti-inflammatory effect on croton oil-induced ear edema in mice (200 mg/kg, inhibition rate 69.8%) and on collagen-induced arthritis in DBA/1 mice (20 mg/kg, inhibition rate 46.0% at day 57).