[Structural Diversity and Its Temporal Variation in the Soil Bacterial Community Under Plantations of Taxodium distichum in the Riparian Zone of the Three Gorges Reservoir Area].

The riparian zone supports important ecological functions and acts as an ecotone connecting terrestrial and aquatic areas. Soil microbes under the revegetation of woody species are crucial to the biogeochemical cycle of nutrients. Here, soil samples were collected to examine the soil microbes during different emergence phases in 2019 (May:T1, July:T2, and September:T3) in the riparian zone of the Three Gorges Reservoir, China. The variations in the bacterial community were evaluated using high-throughput sequencing. The results showed that:during the emergence phases, soil properties such as pH value (pH), ammonium nitrogen (NH4+-N), and nitrate-nitrogen (NO3--N) and soil enzymes changed significantly(P<0.05), and soil bacterial α diversity also changed with time. Except for the Chao1 index, the richness of rhizosphere soil bacteria showed T1>T2>T3, whereas the α diversity of non-rhizosphere soil bacteria showed T3>T1>T2. The redundancy analysis (RDA) test implied that soil urease, NH4+-N, pH, and NO3--N were the key factors structuring the microbial community. Proteobacteria and Acidobacteria were the two dominant components among the 60 phyla that were detected in the soil. Based on phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt2) prediction, metabolism was the basic function of soil bacterial communities of Taxodium distichum; in the secondary functional layer, the metabolic pathways related to carbon, nitrogen, and phosphorus mainly included amino acid metabolism, carbohydrate metabolism, lipid compound metabolism, and energy metabolism, and the relative abundance of each metabolic function had a certain time difference in different periods. These findings could help us better understand how soil microbes change after restoring vegetation in the Three Gorges Reservoir area.

Clinical analysis of bronchoscope diagnosis and treatment for airway foreign body removal in pediatric patients.

BACKGROUND: Along with the wide spread application and technical development of the flexible and rigid bronchoscopy, the airway foreign body removing method cme to the specific technique for different foreign bodies from the single foreign body forceps. METHODS: Selected 633 children who were diagnosed as airway foreign bodies by the Department of Respiratory Intervention, Children's Hospital affiliated to Shandong University from January 1st, 2018 to December 31st, 2021, and the airway foreign bodies were diagnosed using bronchoscopy. After comprehensive assessment of the foreign body nature in the airway, the foreign bodies were removed by freezing, laser, electrocoagulation, balloon and other techniques, the success rate of the foreign body removed from the airway was observed, the percentage of the foreign body removed using different techniques, the operation time, and the incidence of post-adverse reactions during operation. RESULTS: The success rate using flexible bronchoscope alone to remove foreign bodies in the airway was 99.2%. After flexible bronchoscopy, 19 cases of foreign bodies were removed by vacuum suction alone, 513 cases were removed by foreign body forceps alone, 62 cases were combined with cryotherapy, 2 cases were electrocoagulation, 6 cases were mesh baskets, 3 cases were balloons, 5 cases were laser, and various 18 cases of foreign bodies were invloved by technical combination. 5 cases of flexible bronchoscope combined with rigid bronchoscope combined to remove foreign bodies. The operation time was from 5 min to 1 h, with an average of 20 min. There were 17 cases of hypoxemia (2.7%) during operation, 36 cases (5.7%) of bleeding caused by airway mucosa injury after treatment, and 70 cases (11.2%) of laryngeal edema. The total incidence of adverse reactions was 19.6%, there were no deaths due to foreign bodies and treatment. CONCLUSIONS: According to different properties of airway foreign bodies, it is safe and effective to select appropriate techniques to remove foreign bodies using the flexible bronchoscope, which can increase the removal rate of airway foreign bodies and reduce the occurrence of serious complications.

Quantum phases of Rydberg atoms on a frustrated triangular-lattice array.

The neutral atoms coupled to a highly excited Rydberg state on a two-dimensional triangular lattice are investigated by employing the density matrix renormalization group technique in the matrix product state form. The full ground-state phase diagram as a function of blockade radius and the detuning of the exciting laser is determined by the behavior of entanglement entropy. We find several quantum phases including stripe-ordered and symmetry-breaking density-wave-ordered phases featured with regular excitation patterns of different excitation densities ρ = 1/3, 1/4, and 1/7. In addition, a ρ = 2/3 ordered phase and an interesting "order-by-disorder" phase, which has been prepared experimentally, are also observed in this work. Our work provides an exploration of the possible quantum phases that can occur in a triangularly arrayed Rydberg system, and thus could be a faithful theoretical guide for further experimental research.

Multipartite entanglement and quantum criticality of Rydberg atoms trapped in a two-dimensional optical lattice.

We investigate the multipartite entanglement and quantum criticality of neutral atoms on a two-dimensional square lattice, interacting via laser excitation to atom Rydberg states. It is found that the first derivative of residual entanglement with respect to detuning has peaks near the critical point, and corresponding critical behaviors are shown to obey conventional finite-sized scaling, from which we numerically determine the quantum critical point and the critical exponent of the associated correlation length. We also show that there is a sharp peak in the fidelity susceptibility near the critical point, and the critical exponent of the associated correlation length is obtained based on the finite size analysis.

Learning spin liquids on a honeycomb lattice with artificial neural networks.

Machine learning methods provide a new perspective on the study of many-body system in condensed matter physics and there is only limited understanding of their representational properties and limitations in quantum spin liquid systems. In this work, we investigate the ability of the machine learning method based on the restricted Boltzmann machine in capturing physical quantities including the ground-state energy, spin-structure factor, magnetization, quantum coherence, and multipartite entanglement in the two-dimensional ferromagnetic spin liquids on a honeycomb lattice. It is found that the restricted Boltzmann machine can encode the many-body wavefunction quite well by reproducing accurate ground-state energy and structure factor. Further investigation on the behavior of multipartite entanglement indicates that the residual entanglement is richer in the gapless phase than the gapped spin-liquid phase, which suggests that the residual entanglement can characterize the spin-liquid phases. Additionally, we confirm the existence of a gapped non-Abelian topological phase in the spin liquids on a honeycomb lattice with a small magnetic field and determine the corresponding phase boundary by recognizing the rapid change of the local magnetization and residual entanglement.

[Root Activities of Re-Vegetated Plant Species Regulate Soil Nutrients and Bacterial Diversity in the Riparian Zone of the Three Gorges Reservoir].

Plants modify the soil microenvironment through root exudation. It is important to study the dynamic changes of soil ecosystem from the perspective of root-soil-microbe interactions after vegetation restoration in the riparian zone of the Three Gorges Reservoir (TGR). The rhizosphere and bulk soils of Cynodon dactylon, Hemarthria altissima, Taxodium distichum, and Salix matsudana were collected from the vegetation restoration demonstration base of Ruxi River to explore the differences in nutrient contents and enzyme activities between the rhizosphere and bulk soils. At the same time, the diversity of the bacterial community in the rhizosphere and bulk soils was also investigated using the high throughput sequencing method, with the aim to clarify the growth adaptabilities and nutritional utilization strategies within a more precise rhizosphere range. The results showed that ① Suitable plants enhanced the transformation efficiency of rhizosphere nutrients in different ways to improve their adaptability to the soil environment in the TGR. Compared with bulk soil, root activities had significant effects on nutrient contents in the rhizosphere. Among them, SOC, AN, TN, and AP were enriched significantly to a certain degree, while the changes of potassium were not consistent in different plant species. ② In the process of vegetation restoration, the deposition of litter and root secretion indirectly regulated soil enzyme activity. Invertase, urease, and acid phosphatase, all exhibited positive rhizosphere effects (R/S>1) in these four suitable plant species. However, considering the differences in root structure and physiological characteristics between herbaceous and woody plants, the rhizosphere effect of these three enzymes in four plants was different. ③ The results of high-throughput sequencing showed that there was no significant difference in bacterial community diversity between the rhizosphere and bulk soil of four suitable plant species in the TGR. In addition, Proteobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, Planctomycetes, Cyanobacteria, Firmicutes, Nitrospirae, Gemmatimonadetes, WS3, and Crenarchaeota were the twelve most abundant bacterial phyla in the rhizosphere and bulk soils, serving the ecological functions of nutrition absorption and disease suppression. Their colonization was found to be beneficial to the stress resistance of plants growing in harsh riparian ecosystems in the TGR.

The involvement of programmed cell death in inflated leaf petiole morphogenesis in Trapa pseudoincisa.

Trapa plants (Trapaceae) have an inflated leaf petiole called a spongy airbag. The aims of this study were to assess the involvement of programmed cell death (PCD) in the process of inflated leaf petiole morphogenesis. In this paper, light and transmission electron microscopy (TEM) were used to investigate cytological events and the development of inflated leaf petiole. During this process, the inflated leaf petiole of Trapa pseudoincisa L. undergoes a developmental process, changing from solid to hollow phase. Debris from the degraded cells was seldom observed in the transverse sections of leaf petioles, but some degraded cells with an abnormal morphology were observed in longitudinal sections. Cytoplasmic changes, such as disrupted vacuoles, degraded plastids, and the emergence of secondary vacuoles were observed during leaf petiole morphogenesis. In addition, gel electrophoresis and TUNEL assays were used to evaluate DNA cleavage during petiole morphogenesis. DNA internucleosomal cleavage and TUNEL-positive nuclei indicate that the typical PCD features of DNA cleavage occurred early in the process. These results revealed that PCD plays a critical role in inflated leaf petiole morphogenesis. Additionally, a trans-disciplinary systems approach is required that recognises the necessity for integration of cytological and molecular characteristics for identification of aerenchyma type.

Programmed Cell Death and Aerenchyma Formation in Water-Logged Sunflower Stems and Its Promotion by Ethylene and ROS.

Previous studies have shown that waterlogging/ hypoxic conditions induce aerenchyma formation to facilitate gas exchange. Ethylene (ET) and reactive oxygen species (ROS), as regulatory signals, might also be involved in these adaptive responses. However, the interrelationships between these signals have seldom been reported. Herein, we showed that programmed cell death (PCD) was involved in aerenchyma formation in the stem of Helianthus annuus. Lysigenous aerenchyma formation in the stem was induced through waterlogging (WA), ethylene and ROS. Pre-treatment with the NADPH oxidase inhibitor diphenyleneiodonium (DPI) partially suppressed aerenchyma formation in the seedlings after treatment with WA, ET and 3-amino-1, 2, 4-triazole (AT, catalase inhibitor). In addition, pre-treatment with the ethylene perception inhibitor 1-methylcyclopropene (1-MCP) partially suppressed aerenchyma formation induced through WA and ET in the seedlings, but barely inhibited aerenchyma formation induced through ROS. These results revealed that ethylene-mediated ROS signaling plays a role in aerenchyma formation, and there is a causal and interdependent relationship during WA, ET and ROS in PCD, which regulates signal networks in the stem of H. annuus.

[Comparative Studies on Soil Actinobacterial Biodiversity After Re-vegetation in the Urban and Rural Hydro-fluctuation Zone of the Three Gorges Reservoir Region].

This study aimed to understand the soil actinobacterial community diversity in the urban and rural hydro-fluctuation zone of the Three Gorges Reservoir region. The hydro-fluctuation zone of Chongqing Great Theatre in Jiangbei District and the Ruxi river basin in Zhong County, Chongqing, was chosen as the study area. Soil samples were collected in June 2015, to measure actinobacterial biodiversity using the terminal-restriction fragment length polymorphism (T-RFLP) molecular method. Results showed that:1 The actinobacterial biodiversity was different in the urban and rural hydro-fluctuation zone after artificial vegetation restoration. The actinobacterial biodiversity of the urban hydro-fluctuation zone was significantly higher than that of the rural hydro-fluctuation zone (P<0.05), which was most obvious in the surface soil. 2 The actinobacterial biodiversity of woodland was higher than that of grassland, but there was no significant difference in the actinobacterial biodiversity among the three soil layers in both the urban and rural hydro-fluctuation zone. 3 The dominant species of actinomycetes was different in different samples. 4 Redundancy analysis and the Monte-Carlo test revealed that water content and available nitrogen (AN) played a critical role in influencing actinobacterial biodiversity in the urban hydro-fluctuation zone (P<0.05). In contrast, the water content, organic matter (OM), available nitrogen (AN) and available phosphorus (AP) played a critical role in influencing actinobacterial biodiversity in the rural hydro-fluctuation zone of the Three Gorges Reservoir region (P<0.05). Thus, we concluded that the actinobacterial biodiversity of the urban hydro-fluctuation zone was significantly higher than that of the rural hydro-fluctuation zone in the Three Gorges Reservoir region, and such a result was attributed to the increased human disturbance and soil nutrients.

[Evaluation of urban human settlement quality in Ningxia based on AHP and the entropy method].

As one of the key indicators of the urbanization and the sustainable development of cities, urban human settlement quality has been a hot issue. In this paper, an evaluation system containing indicators related to four aspects (ecological, social, humanities and economic environments) was established to assess the urban human settlement quality in five main cities in Ningxia Hui Autonomous Region, Northwest China. After calculating each indicator' s weight in the evaluation system through AHP and the entropy method, the quality of urban human settlement was analyzed. Results showed that Yinchuan had a score of 0. 85 for the quality of human settlement, Shizuishan 0.62, Wuzhong 0.43, Zhongwei 0.33, and Guyuan 0.32, respectively. Shizuishan got the highest score in the eco-environment aspect, and Yinchuan had the highest scores for social, humanities and economic environments. Zhongwei and Guyuan had relatively low scores in all the four urban human settlement aspects. Coordination analysis showed that internal coordination was moderate for Yinchuan (0.79) and Shizuishan (0.72), and relatively good for the other cities. However, coordination was relatively poor among the five cities, especially in social environment (0.48). These results suggested that an unsatisfied situation existed in terms of the urban human settlement quality in Ningxia, and that corresponding measures should be taken to accelerate the development of vulnerable indicators, so as to coordinate all the urban human settlement aspects within and among cities.

[Effects of flooding on the photosynthetic physiology characteristics of Pterocarya stenoptera seedlings].

Three water treatments (control, CK; continuous flooding, CF; and periodic flooding, PF) were installed to simulate the soil moisture change of the riparian zone in the Three Gorges Reservoir (TGR) region of China to study the physiological and ecological adaptation mechanisms of the native plant species Pterocarya stenoptera seedlings to the soil moisture change. All the water treatments had significant effects on the photosynthesis, biomass accumulation, and growth of the P. stenoptera seedlings. As compared with those in CK, the seedling's net photosynthetic rate (Pn) and stomatal conductance (gs) in treatments CF and PF were significantly lower while the intercellular carbon dioxide concentration was significantly higher, and the Pn and gs in CF and PF declined initially followed by a gradual recovery or tended to be stable. With the extension of treatment time, the total biomass and root-, stem-, and leaf biomass, plant height, and basal diameter in CF and PF all presented an increasing trend. Throughout the experimental period, the total biomass, root- and leaf biomass, and plant height in CF and PF and the stem biomass in PF were significantly lower than those in CK, whereas the stem biomass in CF had no significant difference with that in CK, though the basal diameter in CF was significantly higher than that in CK. It was suggested that the P. stenoptera seedlings had the physiological and ecological characteristics of tolerating flooding rather than flooding-drought alteration.