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Two new α-pyrones, micropyrones A (1) and B (2), along with four known γ-pyrones, nocapyrone D (3), nocapyrone A (4), marinactinone A (5), and nocapyrone H (6), were isolated from the culture extract of actinomycete Microbacterium sp. GJ312, which was isolated from Glycyrrhiza uralensis. The structures of these compounds were identified by analysis of spectral data. They are the first α- and γ-pyrones reported from the genus Microbacterium. The antibacterial activity of all compounds against Staphylococcus aureus and methicillin resistant S. aureus was evaluated. However, none of them showed significant activity. This study represents the first phytochemical example of a Glycyrrhiza-derived actinomycete. [ABSTRACT FROM AUTHOR]

Silty soil as a rich reserved subgrade fills in seasonally frozen regions of northern China, experienced at least one freeze-thaw (F-T) cycle each year. Many damages will occur after F-T cycles. In general, using cement to stabilise can alleviate that situation. Hence, a series of unconsolidated and undrained triaxial compression tests were conducted to evaluate the static properties (i.e. cohesion, internal friction angle, shear strength, stress–strain curves and resilient modulus) of cement stabilised silty soil. Meanwhile, the analysis of variance method was adopted to analyse the effects of multiple factors i.e. F-T cycles, confining pressures, water content and cement content on the resilient modulus. The results showed that the cohesion, shear strength and resilient modulus decreased with F-T cycles and water content, while increased with cement content, and tended to be stable after six cycles. The internal friction angle increased with cement content, whereas had no obvious regularities with F-T cycles and water content. The inclusion of cement could transform the stress–strain curves from strain hardening to strain softening, and inhibited the negative impact of F-T cycles and water content on resilient modulus. Based on the above analysis, w opt , 2% cement content and the mechanical property index after six F-T cycles could be used as guidance for actual projects. Moreover, an empirical equation for determining the resilient modulus was proposed and validated. [ABSTRACT FROM AUTHOR]

This long-term fertilization experiment was conducted since 1981, included non-fertilization (NF), chemical fertilizer (CF), double chemical fertilizer (DCF) and chemicals with organic fertilizer (COF). In 2017, soil samples were collected at the tillering, heading and maturity stages of early-season rice (Oryza sativa L.). The activities of urease (UR), α-glucosidase (AG), glucosaminidase (NAG), β-1,4 glucosidase (BG), β-cellobiosidase (CBH), β-xylosidase (BXYL), acid phosphatase (ACP), phenoloxidase (POX) and peroxidase (PER) were measured. The activities of AG, NAG, BG, CBH, BXYL, ACP and POX in the maturity stage were significantly higher than in the tillering stage by 343.0%, 153.4%, 55.0%, 8.5%, 1791.5%, 1237.7% and 1179.4%, respectively. Compared with the CF treatment, the activities of UR, AG, BG, and POX in the COF treatment increased by 33.5%, 23.3%, 19.5% and 40.1%, respectively. Meanwhile, both CBH and ACP in the COF treatment were higher than in the DCF treatment by 33.4% and 66.7%, respectively. A significant relationship was identified between UR/PER activities and soil available nitrogen, phosphorus, potassium/rice biomass using the redundancy analysis method. Therefore, the application of organic and chemical fertilizers could increase most enzymatic activities and soil productivity. UR and PER were key factors indicating soil nutrient turnover and rice growth. [ABSTRACT FROM AUTHOR]

Echinocandin B, a kind of antimycotic with cyclic lipo-hexapeptides, was produced by fermentation with Aspergillus nidulans using fructose as main carbon source. The objective of this study was to screen a high-yield mutant capable of using cheap starch as main carbon source by atmospheric and room temperature plasma (ARTP) treatment in order to decrease the production cost of echinocandin B. A stable mutant A. nidulans ZJB19033, which can use starch as optimal carbon source instead of expensive fructose, was selected from two thousands isolates after several cycles of ARTP mutagenesis. To further increase the production of echinocandin B, the optimization of fermentation medium was performed by response surface methodology (RSM), employing Plackett-Burman design (PBD) followed by Box-Behnken design (BBD). The optimized fermentation medium provided the optimal yield of echinocandin B, 2425.9 ± 43.8 mg/L, 1.3-fold compared to unoptimized medium. The results indicated that the mutant could achieve high echinocandin B production using cheap starch as main carbon source, and the cost of carbon sources in fermentation medium reduced dramatically by about 45%. [ABSTRACT FROM AUTHOR]

The solvothermal reaction of Cd(NO3)2·4H2O with different donor ligands afforded two new Cd(II)-based coordination polymers [Cd(Hcia)(btz)]n (1, H3cia = 5-(4-carboxyphenoxy)isophthalic acid, btz = 4,4'-bi(1,2,4-triazole)) and {[Cd(2,2-bpy)(NO3)2(H2O)](DMA)}n (2, 2,2'-bpy = 2,2'-bipyridine). Complex 1 shows a 3 D 2-fold interpenetrated network based on 1 D infinite [–btz–Cd–btz–] chains, and complex 2 shows 1 D chain-like network based on the 2,2'-bpy chelating Cd centers extended by the NO3- ions. Furthermore, the CCK-8 assay and Annexin V-FITC/PI detection was performed to evaluate the anti-cancer activity of the two complexes against the Hey ovarian cancer cell lines. Western blot was conducted for the mechanism evaluation of the complexes. [ABSTRACT FROM AUTHOR]

Two new germacradiene-type sesquiterpenoids, including 1(10)E,5E-germacradiene-9β,11-diol (or 9β-hydroxyl germacradienol) (1) and 11-hydroxy-1(10)E,5E-germacradien-2-one (2-oxygermacradienol) (2), together with a known geosmin-type sesquiterpenoid (1β,4β,4aβ,7α,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a,7(2H)-triol (3), were elucidated by their NMR spectroscopic data, HR–ESI–MS and single-crystal X-ray diffraction from the halophilic strainNocardiopsis chromatogenesYIM 90109. The antimicrobial activities were evaluated by paper diffusion method. [ABSTRACT FROM PUBLISHER]

This paper investigated sulfadiazine oxidation by the Fenton process under various reaction conditions. The reaction conditions tested in the experiments included the initial pH value of reaction solutions, and the dosages of ferrous ions and hydrogen peroxide. Under the reaction conditions with pH 3, 0.25 mM of ferrous ion and 2 mM of hydrogen peroxide, a removal efficiency of nearly 100% was achieved for sulfadiazine. A series of intermediate products including 4-OH-sulfadiazine/or 5-OH-sulfadiazine, 2-aminopyrimidine, sulfanilamide, formic acid, and oxalic acid were identified. Based on these products, the possible oxidation pathway of sulfadiazine by Fenton's reagent was proposed. The toxicity evaluation of reaction solutions showed increased antimicrobial effects following the Fenton oxidation process. The results from this study suggest that the Fenton oxidation process could remove sulfadiazine, but also increase solution toxicity due to the presence of more toxic products. [ABSTRACT FROM PUBLISHER]

We report new zircon U–Pb and pyrite Re–Os geochronological studies of the Yinjiagou poly-metallic deposit, sited along the southern margin of the North China Craton (SMNCC). In this deposit, pyrite, the most important economic mineral, is intergrown/associated with Mo, Cu, Au, Pb, Zn, and Ag. Prior to our new work, the age of chalcopyrite–pyrite mineralization was known only from its spatial relationship with molybdenite mineralization and with intrusions of known ages. The U–Pb and Re–Os isotope systems provide an excellent means of dating the mineralization itself and additionally place constraints on the ore genesis and metal source. Zircons separated from the quartz–chalcopyrite–pyrite veins include both detrital and magmatic groups. The magmatic zircons confine the maximum age of chalcopyrite–pyrite mineralization to 142.0 ± 1.5 Ma. The Re–Os results yield an age of 141.1 ± 1.1 Ma, which represents the age of the chalcopyrite–pyrite mineralization quite well. The common Os contents are notably low (0.5–20.1 ppt) in all samples. In contrast, the Re contents vary considerably (3.0–199.2 ppb), most likely depending on intensive boiling, which resulted in an increase of Re within the pyrite. This study demonstrates that the main chalcopyrite–pyrite mineralization occurred late in the magmatic history and was linked to a deeper intrusion involving dominant mantle-derived materials. This mineralization event might be related to the Early Cretaceous lithospheric destruction and thinning of the SMNCC. [ABSTRACT FROM AUTHOR]

This article presents experimental investigation on the oxidative treatment of phenol in water by O3/H2O2in a rotating packed bed (RPB). It was found that the phenol degradation ratio increased with increasing rotation speed, initial pH value of phenol solution, and temperature. The degradation ratio of phenol had a peak value with increasing H2O2concentration. The optimum operating conditions in this study were determined as an H2O2concentration of 6.5 mM and a rotation speed of 1200 rpm. Phenol degradation ratio reached 100% at an initial phenol concentration of 40 mg/L in the O3/H2O2process. [ABSTRACT FROM PUBLISHER]

Based on the mechanism of moisture and heat transfer in wood during microwave-vacuum drying (MVD), a one-dimensional mathematical model to describe the process of wood MVD was established and verified by experiments in this research. The results showed that the process of MVD of wood experienced three distinct periods: (1) accelerating rate with rapid warming-up drying period, (2) a constant temperature and constant rate drying period, and (3) a heating-up with falling rate drying period. Compared with conventional hot air drying, the total drying process is almost governed by a constant rate period in vacuum-microwave drying of wood. The predicted temperature and moisture content in wood match well with the experimental data, the square of the relevant coefficient of the values of simulation and test is above 0.9, and the simulation precision of the change rule of the moisture is higher than that of the temperature. [ABSTRACT FROM AUTHOR]

In our study, we sequenced the complete mitochondrial genome of Dactylella tenuis and obtained the complete mitochondrial DNA sequence. This mitogenome is a typical circular molecule of 186,056 bp in length, which is rich in AT (73.79%), including 14 protein-coding genes, 24 transfer RNA genes, and 2 ribosomal RNA genes. Phylogenetic analysis showed the evolutionary relationship between D. tenuis and other species of nematode-trapping fungus. [ABSTRACT FROM AUTHOR]