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Two new guaiane-type sesquiterpenes, wenyujinolides A (1) and B (2), were isolated from the ethanol extract of Curcuma wenyujin, together with 10 known compounds. Their structures were established by extensive spectroscopic methods (IR, ESIMS, HRESIMS, ECD, 1D and 2D NMR) and comparison of their NMR data with literatures. Compounds 1 and 2 were evaluated for the inhibition of NO production in LPS induced RAW 264.7 macrophages. [ABSTRACT FROM AUTHOR]

Two hitherto unknown highly modified abietane diterpenoids, namely salviapritin A (1) and salviapritin B (2), were isolated from the ethanol extract of Salvia prionitis, together with 17 known compounds. Their chemical structures were established by extensive spectroscopic methods (ESIMS, HRESIMS, 1D and 2D NMR) and by comparison of their NMR data with those of related analogues. Salviapritin A is the first example of a trinorabietane diterpenoid possessing an acenaphthylene skeleton from the Salvia genus. Additionally, a plausible biogenetic pathway for salviapritin B is proposed. [ABSTRACT FROM AUTHOR]

Two new triterpenoids, 3-O-(4',5'-dihydroxybenzoyl)-lup-20(29)-en (1) and 3-O-(6'-desmethysyringyl)-13α-methyl-27-norolean-14-en-3β-ol (2), were isolated from the leaves and twigs of Orophea yunnanensis. Their structures were identified by extensive spectroscopic experiments (NMR and MS) and comparison with literature data. Compounds 1 and 2 exhibited the moderate inhibitory activity against Sclerotinia sclerotiorum, Ceratocystis fimbriata and Verticillium dahliae Kleb with MIC values from 50 to 25 μg/mL, and also displayed the weak activity selectively against tested bacteria strains with MIC values from 100 to 50 μg/mL. [ABSTRACT FROM AUTHOR]

A new pregnane steroid, named aspergillon A (1), together with two known compounds, (22E,24R)-ergosta-5,7,22-trien-3β-ol (2) and (22E, 24R)-ergosta-4,6,8(14),22-tetraen-3-one (3) were isolated from cultures of the tin mine tailings-associated fungus Aspergillus versicolor. The new structure and absolute configuration were determined with the help of extensive spectroscopic analyses and quantum chemical calculations of the electronic circular dichroism (ECD) spectra. [ABSTRACT FROM AUTHOR]

To clarify the effect of pH on the structure and functional traits of soil microbial communities in purple soils, three purple upland soils developed from the same parent material that differed in pH were selected as the research objects, and metagenomic shotgun sequencing was used to investigate the structure and functional traits of the microbial communities among different pH soils. The shotgun sequencing identified a total of 89 phyla, 222 classes, 527 orders, 1009 families, 2769 genera, and 14354 species in these soils. Regardless of the phylogenetic classification level, the microbial community structures of these three purple soils with different pHs were significantly different. RDA results corroborated the highly significant difference in the microbial community structures among the three purple soils with different pHs, and the soil properties tested here all had significant correlations with soil microbial community structure, in which the soil pH had the greatest effect ( R 2 =0.9985, P =0.001). However, the results of investigating the microbial community functions revealed that the main metabolic processes of the three purple soils were all involved in unknown functions, global and overview maps, amino acid metabolism, carbohydrate metabolism, ammonia assimilation, etc. There was almost no significant difference in the relative abundance of microbes in the three purple soils annotated with the same function regardless of the COG/KEGG functional database and nitrogen cycling functional database, indicating that the overall function trait of soil microbial community was relatively conservative and not easily affected by environmental factors.

Soil pH is recognized as an important environmental factor in determining the niche differentiation for ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) communities. Species of comammox, a single microorganism capable of the complete oxidation of ammonia to nitrate, have recently been discovered. Metagenomic analysis and quantitative PCR showed that Comammox Nitrospira were found in a wide range of environments, including soil. Comammox bacteria are differentiated into one of two clades (A and B) based on the phylogeny of genes encoding the α-subunit of ammonia monooxygenase genes ( amoA ). However, all discovered Comammox Nitrospira strains have been isolated and cultured in aquatic ecosystems, including N. inopinata, N. nitrosa, and N. nitrificans , all belonging to clade A. Currently, Comammox Nitrospira has not been obtained from soil environments, which limits our understanding of soil Comammox Nitrospira . Here we hypothesized that, as AOA and AOB, the ecological site of Comammox Nitrospira may also be affected by pH. Therefore, soil samples with differing pH were collected, and the abundances and community structures were studied to elucidate the mechanism of pH effect on the distributions and community compositions of Comammox Nitrospira in soil. Quantitative PCR of comammox clade A and clade B amoA genes in DNA extracts were performed using QuantStudio TM 6 Flex Real-Time PCR Systems. The community compositions for Comammox Nitrospira were studied by the cloning libraries of amoA genes method. The results showed that the abundance of Comammox clade A amoA gene in acidic paddy soil was two orders of magnitude higher than that in neutral paddy soil ( P <0.05), and the abundance of Comammox clade B in acidic paddy soil was significantly higher than that in neutral paddy soil ( P <0.05); the abundance of Comammox clade A amoA gene in acidic paddy soil was 60 times higher than that of clade B, whereas the abundance ratio of Comammox clade A and clade B amoA genes in neutral paddy soil was about two times higher. These results indicated that soil pH significantly affected the abundance of Comammox Nitrospira . The results of cloning and sequencing showed that the Comammox in neutral paddy soil was mainly N. inopinata , which belonged to clade A; no strain belonging to clade B was annotated. Comammox clade A in acidic paddy soil was mainly Composed of N. inopinata and N. nitrosa , and clade B was mainly uncultured bacterium (FN395328). The results indicated that soil pH was an important factor in shaping Comammox Nitrospira community structure. Comammox Nitrospira were detected in all soil samples, and Comammox clade A had a preference for acidic environments. It seemed that species from N. nitrosa possessed the ecological niche of low pH environments, whereas species from N. inopinata preferred to live in neutral environments. In conclusion, pH had a significant effect on the abundance and community structure of Comammox Nitrospira , which was one of the important factors affecting the niche differentiation of Comammox Nitrospira .

Nitrogen metabolism pathways mediated by microorganisms play an important role in maintaining the structure and functional stability of soil ecosystems. Clarifying the relationships between microbial communities and nitrogen metabolism pathways can expand our understanding of nitrogen metabolism pathways at a microscopic level. However, the horizontal gene transfer of microorganisms means that taxonomy-based methods cannot be easily applied. A growing number of studies have shown that functional traits affect community construction and ecosystem functions. Using methods based on functional traits to study soil microbial communities can, therefore, better characterize nitrogen metabolism pathways. Here, five typical forest soils in China, namely black soil(Harbin, Heilongjiang), dark-brown earth(Changbaishan, Jilin), yellow-brown earth(Wuhan, Hubei), red earth(Fuzhou, Fujian), and humid-thermo ferralitic soil(Ledong, Hainan), were selected to study the traits of nitrogen metabolism pathways using metagenomic technology combined with the trait-based methods. The studied nitrogen metabolism pathways were ammonia assimilation, nitrate dissimilatory reduction, nitrate assimilatory reduction, denitrification, nitrification, nitrogen fixation, and anaerobic ammonia oxidation. The results showed that bacteria dominated the metagenomic library, accounting for 98.02% of all the sequences. Across all domains, the most common pathway was ammonia assimilation. For example, an average of 2830 ammonia assimilation pathway genes were detected for every million annotated bacterial sequences. In comparison, nitrogen fixation and anaerobic ammonia oxidation were the least detected pathways, accounting for 28.3 and 10.7 per million sequences, respectively. Different microorganisms can participate in a same nitrogen metabolism pathway, and the community structure of different soils was variable. The five typical forest soils in China show the same microbial nitrogen metabolism pathway traits; however, the community structure of the microorganisms mediating these processes was found to vary.

Increasing evidence suggests that ammonia oxidation in acidic soils is primarily catalyzed by ammonia-oxidizing archaea (AOA), while ammonia-oxidizing bacteria (AOB) drive ammonia oxidation in neutral and alkaline soils in which AOA overwhelmingly outnumber AOB. Therefore, neutral purple soil with a pH of 7.2 was selected to study the composition of the active ammoxidation microbial community with a stable isotope nucleic acid probe technique combined with cloning sequencing. Results showed that the nitrification rate was 9.68 mg·(kg·d) -1 , and AOA and AOB were abundant in neutral purple soils. By using DNA-based stable isotope probing (SIP), we gathered strong evidence of archaeal ammonia oxidation by AOA and AOB. Phylogenetic analysis indicated that the Nitrosospira Cluster 3a.1 AOB was dominant in terms of quantity at 0 days, and the Nitrosospira Cluster 3a.2 only accounted for a small part. After 56 days of cultivation, the Nitrosospira Cluster 3a.2 replaced the Nitrosospira Cluster 3a.1 as the active AOB that dominated ammonia oxidation. The AOA that predominated quantitatively at day 0 was Nitrososphaera Subcluster 9, but after cultivation this became Nitrososphaera Subcluster 3.2/3.3. Thus, the community structure of AOA and AOB changed. Active autotrophic nitrification was found in this neutral purple soil. Sequencing analysis of the 13 C-labeled DNA provided robust evidence that both archaea and bacteria played important roles in the nitrification and not all ammonia oxidizers in native soil were active in the nitrification. Phylogenetic analysis clearly showed that the dominant active archaea and bacteria during the incubation were affiliated with Nitrososphaera Subcluster 3.2/3.3 within the soil group 1.1b lineage and Nitrosospira Cluster 3a.2, respectively, which were different from the dominant ammonia oxidizers at the beginning of the incubation. These results suggest that the community structure of ammonia oxidizers can shift quickly upon changes in the substrate availability in soils.

The discovery of the complete ammonia-oxidizing microbes, Comammox Nitrospira , had fundamentally changed our perspective on traditional nitrification. The microbe also played a potentially under-appreciated role in the biogeochemical N cycle and provided a new dimension for the research of nitrification. To investigate the abundance of Comammox in different ecosystems was urgently needed. In the present study, three treatments with different quantities of fertilization in a paddy soil (blank control, NPK and 1.5 NPKS) to investigate the nitrification and amoA gene abundance for nitrifying microorganisms, especially for the complete ammonia oxidizing bacteria (Comammox Nitrospira ). The results showed that:① Both Comammox Clade A and Comammox Clade B were detected in all three treatments, and the abundance of Comammox Clade A were 9.0×10 7 , 1.7×10 8 , 7.2×10 8 copies·g -1 (dry soil), respectively, and for Comammox Clade B were 1.5×10 7 , 1.2×10 7 , 1.7×10 7 copies·g -1 (dry soil), respectively. ② The abundances of both ammonia-oxidizing archaea (AOA)in the three fertilizers was 1.5×10 7 -1.2×10 8 copies·g -1 (dry soil), and the ammonia-oxidizing bacteria (AOB) in the three fertilizers was 2.0×10 5 -9.3×10 7 copies·g -1 (dry soil), lower than the abundance of the Comammox. The ratio of Comammox to AOA was 7.2, and the ratio for Comammox to AOB was 524.4 for blank control, were greater than NPK and 1.5 NPKS treatments. ③ The ratio of Comammox Clade A to Comammox Clade B showed an increasing trend with the increase in fertilizer application, at 6.1, 14.4 and 43.1, respectively. ④ For NPK and 1.5 NPKS treatments, Comammox Clade A amoA gene copies were 1.9 and 8.0 times higher than that of the blank control treatment respectively, and the numbers for AOA significantly increased to 3.2 and 7.2 times that of the blank control. The AOB gene copy numbers increased by two orders of magnitude compared with the blank control. In addition, the nitrification potential increased with the increase in N fertilizer application; however, the effects of different fertilizer treatments on Comammox Clade B were not significant. Results indicated that Comammox was widely distributed in the neutral purple paddy soil and was higher in abundance than AOA or AOB, which implied that Comammox-especially Clade A-may contribute to the nitrification of paddy soil.

Acidic forest peat soil in Xiaoxing'an Mountain was used to investigate the type and key drivers of nitrification by carrying out nitrification incubation after adding 10 mL·L -1 C 2 H 2 and different amounts of (NH 4 ) 2 SO 4 (0, 1.2, 6.0 mmol N·kg -1 ). Results showed that strong mineralization (0.9-1.4 mg N·kg -1 ·d -1 ) and nitrification (0.4-0.6 mg N·kg -1 ·d -1 ) after 2 weeks of incubation were observed for both nitrogen and no nitrogen treatments, and no significant difference was observed for different (NH 4 ) 2 SO 4 application treatments. For C 2 H 2 treatment, there was relatively stronger mineralization (0.8 mg N·kg -1 ·d -1 ), but no obvious nitrification (0 mg N·kg -1 ·d -1 ). These results indicated that the nitrification in acidic peat soil was mainly autotrophic, and inorganic nitrogen application did not affect nitrification rate significantly. Results also implied that the substrate (NH 3 ) for nitrification was from the organic N mineralization, rather than the (NH 4 ) 2 SO 4 application. Both ammonia-oxidizing bacteria (AOB) and archaea (AOA) abundances increased significantly during 0-14 d regardless of nitrogen application. However, no significant difference in AOB and AOA abundances for different (NH 4 ) 2 SO 4 application treatments was observed, indicating that ammonia oxidizers did not respond positively to (NH 4 ) 2 SO 4 application. Compared with the treatments without C 2 H 2 , AOB and AOA abundances did not change significantly during the incubation in C 2 H 2 treatment, suggesting that both AOA and AOB were likely the key players in nitrification in the acidic peat soil.

Nitrification is the process of microbial oxidation of ammonia to nitrate, completed by the ammonia oxidizers (AOB and AOA) and nitrite oxidizing bacteria (NOB), sequentially. For a century, we have been learning and studying the established two-step process as the unique way for nitrification. According to the kinetic theory, there should be a one-step nitrification in the environment, that is, the whole process of nitrification (from NH 3 to NO 3 - ) was completed by one microorganism, but no study could give a direct proof for the existence of this microorganism. Until the end of 2015, three different cultivated bacteria (Candidatus Nitrospira nitrosa, Candidatus Nitrospira nitrificans and Candidatus Nitrospira inopinata) and an uncultivated bacterium (Nitrospira-like orga-nism) respectively found in different environments by three research teams, were defined as complete ammonia oxidizing microorganisms (Comammox), because all of them could carry out the complete oxidation of ammonia to nitrate. The discovery of one-step nitrification and Comammox ended the 100-year-old dogma, and triggered many important scientific issues of the global nitrogen cycle, such as the ecological niche of these microorganisms in the environment and their relative contribution in nitrification. This paper made a brief overview of the discovery of one-step nitrification and Comammox.

Coastal wetlands contribute about 75% to the global oceanic CH 4 emissions, thus play a vital role in global C cycles. In this paper, we provided a perspective on researches on metabolic, phylogenetic, and ecological diversity of the methanogenic archaea and the regulating environmental factors in coastal wetlands. Because of the presence of more favorable electron acceptors such as sulfate, methanogenesis via CO 2 reduction and acetate fermentation are limited by availability of substrates, and hydrogenotrophic and acetotrophic methanogens generally express low relative abundance. In contrast, "non-competitive" substrates such as methanol and methylated compounds have been shown to contribute substantially to methane formation in coastal wetlands, and the facultative methanogens are predominant in those environments. Salinity regulates vegetation zonation and is related to SO 4 2- concentration, by regulating types of methanogenic substrates and contents of compe-titive electron acceptors, indirectly affects the structure and function of methanogens. Major uncertainties in the current studies include the following: methanogen community structure, the key environmental factors regulating methane pathway, and their effects on methane emissions in coastal wetlands.

Aim: To investigate the efficacy and safety of percutaneous needle decompression in the treatment of malignant small bowel obstruction (MSBO)., Methods: A prospective analysis of the clinical data of 52 MSBO patients undergoing percutaneous needle decompression was performed., Results: Percutaneous needle decompression was successful in all 52 patients. Statistically significant differences were observed in symptoms such as vomiting, abdominal distension and abdominal pain before and after treatment (81.6% vs 26.5%, 100% vs 8.2%, and 85.7% vs 46.9%, respectively; all P < 0.05). The overall significantly improved rate was 19.2% (11/52) and the response rate was 94.2% (49/52) using decompression combined with nasal tube placement, local arterial infusion of chemotherapy and nutritional support. During the one-month follow-up period, puncture-related complications were acceptable., Conclusion: Percutaneous needle intestinal decompression is a safe and effective palliative treatment for MSBO.