[Soil Microbial Community Structure and Functional Diversity Character of Abandoned Farmland in Minqin Oasis].

To clarify the impact of the structure and function of soil microbial communities in the stage of abandoned farmland, three different stages of land abandoned in desert oasis areas were selected as the research objects. We used metagenomic sequencing technology to research soil microbial community structure and functional diversity characteristics of different stages of abandoned farmland. The results showed that there were significant differences in the relative abundance of the dominant phyla Actinobacteria, Proteobacteria, and Gemmatimonadetes in the soil of the three stages of returning farmland. Compared with that in the early stage of abandoned farmland, the later stage of abandoned farmland restoration increased the gene proportion involved in Quorum sensing, porphyrin and chlorophyll metabolism, pantothenate and CoA biosynthesis, and styrene degradation, and there was a significant difference in relative abundance (P<0.05), which indicated that different stages of abandoned farmland had changed the functional potential of the nutrient cycle and energy metabolism in soil microbial communities. The RDA results showed that EC, AK, and TN had a significant impact on the functional composition of soil microbes, and soil EC had the greatest impact on microbial functional composition. The results showed that different stages of abandoned farmland had a significant impact on the soil microbial community structure and functional composition. In the ecological restoration of abandoned farmland in Minqin Oasis, the sensitivity of microbial community structure and functional composition to soil restoration at different stages should be considered using comprehensive relevant indicators.

Ecological Risk Assessment and Source Identification of Heavy Metals in Soils from Shiyang River Watershed in Northwest China.

Shiyang River Watershed is an important ecological barrier and agricultural production area in Northwest China, and the study of soil heavy metal content, distribution, and sources is important for agricultural product safety, pollution control, and ecosystem health. In this paper, 140 soil samples were collected from 28 stations to assess the level of heavy metal (Arsenic (As), Copper (Cu), Lead (Pb), Cadmium (Cd), Chromium (Cr), Mercury (Hg), Nickel (Ni), Zinc (Zn)) contamination, pollutant sources and influencing factors of soil in Shiyang River Watershed through determination of the metal contents and statistical analysis. The results indicated that the soils in the study area are typical saline soils in arid zones. The enrichment factors (EF) of As, Cr, Cu, Ni, Zn, and Pb indicate no contamination, and the EFs of Cd and Hg suggested minor contamination. Although the concentrations of Cd and Hg in soil are lower than others, they are more biotoxic and exhibit a moderate-high ecological risk. The index of geoaccumulation (Igeo) values reflect that most of the stations, especially the three groups of samples from depths of 10-20 cm, 20-40 cm, and 40-80 cm, are below the contamination threshold for all heavy metals. The chemical speciation of heavy metals, principal component analysis, and correlation analysis showed that Cr, Cu, Pb, Cd, Ni, and Zn mainly come from the natural accumulation upon weathering of soil-forming matrices. Hg and As mainly come from anthropogenic contributions. The effect of agricultural crop cultivation on soil heavy metal contamination is mainly through farm irrigation and crop-soil interactions, which accelerate the release of heavy metals through the weathering of soil-forming parent material and irrigation, which transports the heavy metals below the surface. The results of this study can provide a scientific basis for the involved authorities to formulate reasonable policies on environmental protection and pollution control.

Metagenomic next-generation sequencing for the diagnosis of Chlamydia psittaci pneumonia.

The aim of this study was to investigate the clinical characteristics of Chlamydia psittaci pneumonia and evaluate the diagnostic value of Metagenomic Next-Generation Sequencing (mNGS). A total of 44 patients diagnosed with Chlamydia psittaci pneumonia using mNGS were retrospectively analysed. The demographic and clinical features, laboratory data, imaging findings and clinical outcomes were collected. Results showed that 65.91% of the patients had a history of exposure to poultry or birds. All patients presented with fever. Apart from systemic and respiratory symptoms, some patients also presented with digestive and neurological symptoms. Respiratory failure was common among patients. The key laboratory tests were normal white blood cell counts, slightly elevated PCT, changes in levels of cardiac enzymes, liver enzymes and hyponatremia. Chest imaging revealed that most of the lesions contained patchy exudation or lobar consolidation of one lobe, especially in the lower lobe. Consolidation of both lungs was seen in critically ill patients. Although quinolones were effective in most patients, tetracyclines should be the first choice of treatment. The overall prognosis was good; however, patients who developed severe pneumonia had poor prognosis. The incidence of chlamydia psittaci pneumonia may be underestimated due to the nonspecific clinical manifestations and lack of confirmatory testing methods. The use of mNGS has increased the number of patients diagnosed with chlamydia psittaci pneumonia. mNGS is an effective diagnostic method for chlamydia psittaci pneumonia.