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An organic photoredox-catalyzed

In this study, an innovative method was used to assess the spatial and temporal patterns of the hydrological connectivity in soil profiles in the Yellow River Delta wetland. In this method, field dye-tracing experiments conducted in the study area (i.e., large [LWa] and small communities [LWb] of Phragmites australis and Suaeda glauca [JP]) were considered, and the root-soil interface in the region and the status of the wetland degradation were analyzed. The results revealed that the index of hydrological connectivity (IHC) significantly changed both spatially and temporally. The high IHC values reaching a 0.392 ± 0.209 gradient were concentrated in the middle and western parts of the study areas. The spatial distribution of the high hydrological connectivity has been extremely fragmented since 2010. The LWb (severely degraded wetland) and JP (extremely degraded wetland) were found to be more seriously degraded than the LWa (moderately degraded wetland) in the study area. The changes in the IHC were positively correlated with the principal component (PC) values of the wetland degradation. The IHC is a novel indicator of the status of wetland degradation. Furthermore, the soil holding capacity, soil non-capacity porosity, and soil ventilation were relatively important for the changes in the IHC. Compared with the soil properties, the hydrological responses of the roots systems can be neglected at the root-soil interface. Based on our results, we propose an alternative wetland restoration solution for the Yellow River Delta wetland: 1) a seepage layer in the surface soils (0–10 cm), shallow ploughing treatment, and litter or straw return to the soil surface should be conducted to increase the hydrological connectivity of the soil surface; 2) reeds should not be reaped every year to remove the nutrients from this area; and 3) appropriate freshwater inputs should be strengthened.

The invasion of Spartina alterniflora (S. alterniflora) has caused serious damage to coastal wetland ecosystems in China, especially the mangrove wetlands in South China. This study aimed to validate the effect of imazapyr on S. alterniflora and soil. The controlled experiment was conducted in May 2021 at the Zhangjiangkou Mangrove Wetland Reserve. In the experiment, 25% (W) imazapyr was used, and six treatments were set up: 3035, 6070, and 9105 mL/acre 25% imazapyr and 1299, 2604, and 5202 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr. The results showed no side effects on mangrove plants in the spraying area. The highest control efficiency (95.9%) was given by 2604 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr. The residues of imazapyr in different soils were reduced to 0.10–0.59 mg/kg. The sequencing results showed no significant difference in the overall bacterial communities under different treatments (p &gt, 0.05). The soil bacterial diversity in the samples with adjuvant was higher than that in the samples without adjuvant, while the abundance values were the opposite. There were 10 main communities (&gt, 0.3%) at phylum level in all soil samples, among which Proteobacteria, Bacteroidetes, Acidobacteria, Chloflexi, and Actinobacteria were the dominant communities, and the latter four’s abundance changed significantly (p &lt, 0.05). There were significant abundance differences between the groups of oligotrophic and eutrophic bacteria. The redundancy analysis and Monte Carlo tests showed that the total organic carbon (TOC), total phosphorus (TP), available phosphorus (AP), ammonia nitrogen, and total nitrogen were the main factors affecting soil bacterial diversity. At the same time, TOC, AP, and TP were the most critical factors affecting the overall characteristics of soil bacterial communities in different treatments, while soil residues had no significant effect on bacteria. This might be due to the addition and degradation of imazapyr and the coverage of S. alterniflora. The best recommendation is 2604 mL/acre of AGE 809 + 6070 mL/acre 25% imazapyr to be applied in China’s mangrove wetland reserves and coastal wetlands.

Wetlands are one of the world’s three major ecosystems. They not only maintain regional ecological balance but also provide an important guarantee for human survival. Wetland ecosystem health assessment serves as the foundation for wetland protection, management, and restoration. In this study, the method for wetland ecosystem health assessment proposed by the United States Environmental Protection Agency (US EPA) was selected and improved to systematically evaluate the health status of the Cuihu wetlands’ ecosystem at three levels. The results revealed that the Cuihu wetlands’ landscape development intensity index was 1.55, the total landscape pattern value was 10 points, and the total score for rapid evaluation was 0.79. Levels I and II indicated that the Cuihu wetlands’ ecosystem was in a good near-natural state. Additionally, level III revealed that ecosystem health is higher in area B than in area A. The Cuihu wetlands were characterized by low species diversity and low distribution of benthic animals and aquatic plants. The comprehensive evaluation results revealed that the Cuihu wetlands’ ecosystem is in a good health. In the future, the health status of the wetland ecosystem should be monitored regularly, the cultivation and propagation of aquatic plants should be strengthened, and effective methods to improve water quality and reduce soil salinity should be used to achieve the best health status of the Cuihu wetlands.

The soil column samples were collected for indoor simulated freeze-thaw experiments to monitor the soil hydrothermal dynamics and measure the basic physicochemical properties to research the effects of freeze-thaw on the hydrothermal process of peat bog soil and its relationship with physicochemical properties. The results indicate that in the initial phase of freezing-thawing, soil water content decreases and soil temperature changes, respectively. Unfrozen water content in soil in the stable freezing period decreases sharply. Compared with the freezing period, the fluctuation of soil moisture rate during thawing is more moderate with the temperature change. Soil ammonium nitrogen content decreases with decreasing soil temperature and is significantly positively correlated with soil water content after freeze-thaw, while total phosphorus, fast-acting phosphorus, total nitrogen and nitrate have no significant correlation with soil temperature and soil moisture content after freeze-thaw.

To explore the spatial heterogeneity of pH and cadmium (Cd) content in the soils of the tea gardens in the plateau mountain regions as well as its driving factors, the pH values, Cd content and other physical and chemical indicators from 423 soil samples were examined. A coefficient of variation method and a semivariance function model was adopted to explore the soils’ spatial heterogeneity, and a random forest approach was applied to evaluate the factors influencing environmental Cd under different pH values. The results show that the pH values of the soils of the tea gardens in the plateau mountain regions were within the appropriate range for the growth of tea plants, and soil samples with pH values falling between 4.5 and 6.0 account for 74% of all samples. A comparison against the criteria of risk screening values for the contamination of agricultural land, a component of quantifying soil environmental quality in China, was preformed; it was determined that the content of heavy metal Cd in the soil of the tea gardens did not exceed the limit. The content of soil pH in the research area gradually declined from southwest to northeast, exhibiting two distinct parallel distribution zones running along the southwest-northeast direction. The spatial distribution of the heavy metal Cd content in the soil showed a gradually decreasing trend from north to south, with low-value polygons dominantly appearing in the southeasternmost area and high-value polygons concentrated in the north. When the soil pH ≤ 5.5, it had the largest effect on the Cd content; when 5.5

The first palladium-catalyzed Hiyama cross-coupling of arylsilanes with benzyltrimethylammonium salts is reported. The reaction proceeds smoothly to facilitate C(sp2)-C(sp3) bond formation via cleavage of the C-N bond and provides a useful approach to various diarylmethanes with a broad substrate scope and excellent functional group tolerance in good to excellent yields.

Firstly, based on the research of intelligent manufacturing, the thesis analyses the birth and development goals of the Internet of Things and its application in intelligent manufacturing. It sorts out the existing IoT application technology problems in the manufacturing industry and explains the urgency of this research. The paper then analyses the characteristics of high-end assembly fault diagnosis and early warning system in the manufacturing IoT environment, and explains the connotation and characteristics of the system; constructs the overall operation framework, network environment and topology structure; and realizes system construction. Finally, the paper uses the actual case to simulate the application of the system, which verifies the feasibility and effectiveness of the research.

Particulate matter (PM) in the atmosphere is a threat to human health. Wetland plants were confirmed to accumulate particles on the leaf surface; at the same time, rainfall could wash-off particles and accelerate the whole removal process, however, the dynamic processes occurring during rainfall events on wetland plants remain unclear. In order to provide sustainable strategies for authorities to take measures, we need to figure out how to reduce PM on leave surface by artificial rainfall efficiently. Four wetland species (Scirpus validus, Typha orientalis, Phragmites australis, and Iris wilsonii) were selected to examine for leave surface accumulation and simulate the experiment. We estimated the wash-off ability of rainfalls with three different intensities (15, 30, and 60 mm h−1) and determined the proportions of different PM size-fractions washed by the rains. The results showed that particles accumulated on the surface could be washed off efficiently (78% ∼ 89%) by the simulated rainfalls. The removal rates were high in the first 30 min and large particles comprised a large proportion of the removed particles. The rainfall with the intensity of 30 mm h−1 removed the most particles among three different rainfall intensities. When the rainfall intensity increased, fine particles (PM2.5) could be washed off more easily. Moreover, with a thinner wax layer, fine particles on wetland plants’ leaf surfaces might be more easily removed by the rains. While wash off the plants, spraying rains with the intensity of 30 mm h−1 for about 30 min every time (high intensity with shorter time) may be particle removal efficiency.

To determine the impact of three different regions of interests (ROIs) positioning methods for apparent diffusion coefficient (ADC) measurements on the assessment of the grade and recurrence and to examine the correlation between ADC value and histopathological grade/ Ki-67 labeling index (LI) in patients with bladder cancer.Sixty-one patients with bladder cancer were retrospectively evaluated. Two observers measured mean ADC values using whole-volume-ROIs, single-section-ROI and three-ROIs methods. Interclass correlation coefficient was analyzed to assess interobserver variability. The grade and recurrence in patients with bladder cancer were assessed by calculating the areas under the receiver operating characteristic curves with Az values. Spearman's correlation was used to analyze the correlations of ADC value with grade and Ki-67 LI.For the mean ADC value, the interclass correlation coefficient were excellent with the whole-volume and the single-section method (0.90 [95% CI: 0.84, 0.94] and 0.89 [95% CI: 0.81, 0.93]) and was good with the three-ROIs method (0.72 [95% CI: 0.53, 0.83]). The Az value for determining histological grade and recurrence of bladder cancer were not significantly different from each positioning method (all p0.05). There's significant correlation between histological grade and ADC measuring by whole-volume-ROIs and single-section-ROI methods (r = 0.31, p = 0.02; r = 0.37, p0.05). The ADC measured by whole-volume-ROIs, single-section-ROI, and three-ROIs methods were significantly and inversely correlated with the Ki-67 LI (r = -0.3; r = -0.49; r = -0.40, all p0.05).There's no significant difference among any of the ROI positioning methods in evaluation of tumor grade and recurrence. There's significant correlation between histological grade and ADC measuring by whole-volume-ROIs and single-section-ROI methods. The ADC value obtained by either of three methods was significantly and inversely correlated with the Ki-67 LI.

In recent years, scholars have paid increased attention to the ecological role of crab burrows, particularly their impact on the hydrological processes of saltmarsh wetlands. This study aims to investigate the influence of crab burrows on soil water and salt transport and to understand the ecological significance of crab burrows in coastal wetlands from the perspective of ecohydrological processes. We combined a field sample survey and an indoor soil column infiltration experiment to analyze the differences in infiltration time, soil water content, and soil electrical conductivity (EC) between different experimental groups. Consequently, the results showed that the size of crab burrow diameter varies significantly in different areas of the coastal wetland, influenced by tidal creek and sea-land distances, with larger burrow diameters in areas around 5 m from the tidal creek. Large-diameter burrows (2.5 cm × 6) are more conducive to salt transport due to their preferential water conductivity to the underlying soil vertically, small-diameter burrows (0.5 cm × 6) could promote water infiltration uniformly and maintain good soil water retention capacity. This study's results provide insights into the hydrological connectivity and spatial distribution of salinity in coastal wetlands. Additionally, the positive impact of burrows on the water-salt environment of coastal wetland sediments may also provide new ideas for coastal wetland restoration.

Femoral condyle motion of the knee is generally reported using a morphological trans-epicondyle axis (TEA) or geometric center axis (GCA) in the investigation of the knee kinematics. Axial rotation of the femur is recognized as a characteristic motion of the knee during flexion, but is controversial in the literature. This study investigated the biomechanical factors that could be associated to the axial rotations of the femur using both physiological and morphological measurement methods. Twenty healthy knees were investigated during a weightbearing flexion from 0° to 120° at a 15° increment using an imaging technique. A 3D model was constructed for each knee using MR images. Tibiofemoral cartilage contact points were determined at each flexion position to represent physiological knee motion. The contact distance on each condyle was measured between consecutive contact points. The TEA and GCA were used to measure morphological anteroposterior translations of the femoral condyles. The differences between the medial and lateral condyle motions were used to calculate the physiological and morphological axial rotations of the femur. Both the physiological and morphological methods measured external rotations of the femur at low flexion range (0°-45°) and minimal rotations at higher flexion angles. However, the morphological method measured larger posterior translations of the lateral femoral condyle than the medial condyle (p 0.05), implying a medial pivoting rotation; in contrast, the physiological method measured larger contact distances on the medial condyle than on the lateral condyle (p 0.05), implying a lateral pivoting rotation. These data could provide useful references for future investigation of kinematics of the knee before and after surgical repair, such as using total knee arthroplasty.

The spatial distribution patterns of soil organic carbon (SOC) and its relationship with various environmental factors in different topographic features are of great significance for evaluating SOC reserves and carbon pool management in karst areas. In this paper, SOC from the non-karst landforms and four typical karst landforms (karst canyon, karst peak cluster, karst plateau, and karst trough valley) was selected as the research object. The distribution patterns and the driving factors of SOC in the typical landforms were investigated from the topographical and environmental perspectives. The results showed that the average content of organic carbon in non-karst region was 9.39 g/kg, while that in karst areas was 16.31 g/kg. The vertical changes in SOC content showed different patterns in different topographic features, and each layer of the soil profile showed that SOC content in karst regions was greater than that in the non-karst one. The driving factors for SOC varied in different landforms. Specifically, in non-karst and karst peak cluster areas, slope gradient was the key factor influencing SOC. In karst canyon areas, soil thickness was the key factor influencing SOC. In karst plateau areas, land utilization was the key factor influencing superficial SOC. In karst trough valley areas, rock exposure was the major driving factor for karst SOC. These findings could provide an excellent explanation for the factors influencing SOC in karst and non-karst regions in Southwest China.

BACKGROUND Wearable health care devices have not yet been commercialized on a large scale. Additionally, people in different countries have different utilization rates. Therefore, more in-depth studies on the moderating effect of national culture on adoption intention in wearable health care devices are necessary. OBJECTIVE This study aims to explore the summary results of the relationships between perceived usefulness and perceived ease of use with adoption intention in wearable health care devices and the impact of the moderating effect of national culture on these two relationships. METHODS We searched for studies published before September 2021 in the Web of Science, EBSCO, Engineering Village, China National Knowledge Infrastructure, IEEE Xplore, and Wiley Online Library databases. CMA (version 2.0, Biostat Inc) software was used to perform the meta-analysis. We conducted publication bias and heterogeneity tests on the data. The random-effects model was used to estimate the main effect size, and a sensitivity analysis was conducted. A meta-regression analysis was used to test the moderating effect of national culture. RESULTS This meta-analysis included 20 publications with a total of 6128 participants. Perceived usefulness (r=0.612, Pr=0.462, PPPPPPPPP CONCLUSIONS This meta-analysis provided comprehensive evidence on the positive relationship between perceived usefulness and perceived ease of use with adoption intention and the moderating effect of national culture on these two relationships. Regarding the moderating effect, perceived usefulness and perceived ease of use have a greater impact on adoption intention for people in individualistic, masculine, low uncertainty avoidance, and indulgence cultures, respectively.

Background Wearable health care devices have not yet been commercialized on a large scale. Additionally, people in different countries have different utilization rates. Therefore, more in-depth studies on the moderating effect of national culture on adoption intention in wearable health care devices are necessary. Objective This study aims to explore the summary results of the relationships between perceived usefulness and perceived ease of use with adoption intention in wearable health care devices and the impact of the moderating effect of national culture on these two relationships. Methods We searched for studies published before September 2021 in the Web of Science, EBSCO, Engineering Village, China National Knowledge Infrastructure, IEEE Xplore, and Wiley Online Library databases. CMA (version 2.0, Biostat Inc) software was used to perform the meta-analysis. We conducted publication bias and heterogeneity tests on the data. The random-effects model was used to estimate the main effect size, and a sensitivity analysis was conducted. A meta-regression analysis was used to test the moderating effect of national culture. Results This meta-analysis included 20 publications with a total of 6128 participants. Perceived usefulness (r=0.612, P Conclusions This meta-analysis provided comprehensive evidence on the positive relationship between perceived usefulness and perceived ease of use with adoption intention and the moderating effect of national culture on these two relationships. Regarding the moderating effect, perceived usefulness and perceived ease of use have a greater impact on adoption intention for people in individualistic, masculine, low uncertainty avoidance, and indulgence cultures, respectively.

Wetland ecosystem, with their precious natural resources and important ecological functions, is an integral part of the global ecosystem. Preferential flow is a form of water and solute transport that is widely present in all types of soils and has a great impact on nutrient transport and environmental pollution in soils. In this paper, we observe the phenomenon of preferential flow within a wetland ecosystem and discuss the possible effects of preferential flow within a wetland on the wetland ecosystem as a background. We conducted dye tracing experiments outdoors. The preferential flow was qualitative analysis using soil composition. It was found that two types of preferential flow existed in the experimental area, namely finger flow and macropore flow. Quantitative analysis of the preferential flow was performed using PS and Image-Pro Plus software to obtain the intensity data of the preferential flow. The results show that the preferential flow phenomenon in the experimental area is obvious and the preferential-flow intensity data is high. We also found a clear correlation between initial soil–water content, which is an environmental factor characteristic of wetlands, and the preferential-flow data (p = 0.04

The design of the transformer can withstand the mechanical shock during transportation and the large electromechanical power generated by short circuit and switching surge current. However, due to these forces, the windings may be slack, misaligned or deformed. The windings are the core component of the transformer, which directly affects the diagnosis of the transformer and even the entire power system. This paper proposes a feature extraction method for transformer winding vibration signals based on improved variational modal decomposition (IVMD). The improved variational modal decomposition is used to decompose the vibration signals under different states of transformer windings into a series of finite bandwidth eigenmode functions (IMF); on the basis of feature extraction, this paper also introduces the correlation vector machine (RVM), through the pattern recognition algorithm to establish the relationship between the weight divergence and the transformer winding operating conditions, and through the harmony search algorithm to optimize the option to the RVM kernel function. The algorithm proposed in this paper can effectively extract the characteristics of the mechanical vibration signal of the transformer winding and improve the classification accuracy of RVM.

The initial configuration of Yttrium oxide clusters (Y2O3)n(n=1-15) was creatively constructed by combining artificial bee colony algorithm with density functional theory. The structures of large and medium-sized yttrium oxide clusters with molecular number greater than 10 were established for the first time, and many new structures that are different from existing research have been obtained. The average binding energy, second-order difference energy, HOMO-LUMO gap, density of states and other properties of the clusters were analyzed. The thermodynamic properties and behavior of nano yttrium oxide clusters at different temperatures and sizes were discussed. Studies have shown that for small-sized clusters, the atomic stacking structure is cage-like, while for medium-sized and large-sized clusters, the composite trapezoidal structure and ellipsoid-like structure are more stable. The nanoclusters tend to be stable as a whole, and the relative stability of the cluster structure is higher when n = 2,4,7,9. The effect of yttrium oxygen atomic orbital on bonding is analyzed. The heat capacity (Cp), enthalpy change (H) and entropy (S) of (Y2O3)n (n=1-15) clusters increase with the increase of temperature (T), and the vibration free energy (Gv) decreases with the increase of T. The stability of the clusters changes in the temperature range of 300K-500K.

Growing populations and industrialization have led to raised wetland ecosystems nitrogen(N) loads. A micro constructed wetland planted with Lythrum salicaria L treating an artificial wastewater was used to investigate the short-term variations in the plant biomass and the removal efficiency of N. Our results showed that the biomass of Lythrum salicaria L. increased rapidly during the experiment due to their extensive root system and vigorous spread, and waterlogged conditions had little effect on the relationship between biomass and the concentration of TN in soil and effluent. Under different waterlogged conditions, the removal rates of TN in the water were all more than 60%, providing a reference for waterlogged conditions used in wetland eutrophication restoration.

Gap balance of the knee at 0° and 90° of flexion has been pursued in total knee arthroplasty (TKA) with the trans-epicondyle axis (TEA) as a reference. This study investigated the height changes of the tibiofemoral articulation and compared the data with the femoral condyle height changes measured using different flexion axes.Twenty healthy knees were investigated during an in vivo weightbearing flexion using a technique combining MRI and a dual fluoroscopic imaging system (DFIS). The tibiofemoral contact points and the femoral condyle heights [measured using: TEA, geometric center axis (GCA), and iso-height axis (IHA)] were determined at each flexion angle. The height changes of the articular contact points and the femoral condyles were compared along the flexion path.The changes of the medial and lateral contact point heights were within 2.5 mm along the flexion path. The changes of the medial and lateral condyle heights were within 8.9 mm for TEA, within 4.2 mm for GCA and within 3.0 mm for IHA. The height changes measured by the contact points and IHA are similar (p 0.05), and both are significantly smaller than those measured using the TEA and GCA (p 0.05).The TEA and GCA measured varying femoral condyle heights, but the IHA resulted in minimal condyle height changes and could better represent the articulation characteristics of the knee. The data suggested that the IHA could be used as an alternative reference to guide surgical preparation of gap balance along the knee flexion path during TKA surgeries.

Management intensity was considered an important factor in evaluating and regulating the anthropogenic restoration measures for a degraded ecosystem. By comparing selected conventional soil physicochemical, microbial and incorporating aggregate-associated indices between wetland plot with high-intensity freshwater replenishment (HI wetlands) and wetland plot with low-intensity freshwater replenishment (LI wetlands), edaphic responses of degraded estuarine wetlands to freshwater replenishment at different intensity were assessed in the present study. The results showed that high-intensity freshwater replenishment exerted better soil salinization and alkalization alleviation effects on degraded estuarine wetlands, which caused lower EC and pH values in HI wetlands than those in LI wetlands. And soil microbial biomass was promoted, with freshwater replenishment intensity increased, as indicated by MBC and total PLFAs. Minor alternation of soil microbial community composition was observed with an elevated abundance of arbuscular mycorrhizal fungi (AMF) in HI wetlands. On the other hand, freshwater replenishment at low intensity was found to contribute to organic matter accumulation, as indicated by both higher SOC concentrations and carbon stocks in LI wetlands than those in HI wetlands. And soil aggregate-associated indicators provided more scientific clues that freshwater replenishment at low intensity favored the formation of large macroaggregates, and thus supported higher soil aggregate stability. Moreover, a transfer of allocations of aggregate-associated carbon and nitrogen stocks from microaggregates to large macroaggregates was induced as the freshwater replenishment intensity decreased, and the principle governing factors were the proportion of large macroaggregates in soils, soil salinity and microbial decomposition rates based on multivariate statistical analysis. The findings of this study could provide basic data regarding soil physicochemical properties, microbial characteristics and soil structure stability in restored wetlands of the Yellow River Delta with freshwater replenishment at different intensity and guiding adaptive management strategies of freshwater replenishment to enhance the ecological functions of estuarine wetlands.

AimsAtherosclerosis underlies most cardiovascular diseases, among which acute coronary syndrome (ACS) caused by plaque rupture (PR) often leads to death. Immune-related GTPases (IRGM/Irgm1) have been extensively studied in inflammatory diseases, but their role in atherosclerosis is unclear. Determining how IRGM/Irgm1 promotes atherosclerotic plaque vulnerability will provide information for new biomarkers and/or therapeutic targets.Methods and resultsWe identified ruptured and unruptured plaques by optical coherence tomography, and found that serum IRGM was highly expressed in patients with ST-segment elevation myocardial infarction in PR. We used ApoE-/-Irgm1+/+, ApoE-/-Irgm1+/- mice and chimeric mice to establish a model of advanced atherosclerosis. The results of pathological experiments showed that Irgm1 caused plaque necrosis. The ratio of neutral lipids and cholesterol crystals increases, while the content of collagen fibers decreases, aggravating the destabilization of atherosclerotic plaques. In vitro, we used multiple approaches to confirm that Irgm1 promotes macrophage apoptosis by promoting the production of reactive oxygen species and activating the MAPK signaling pathway.ConclusionsIRGM may be a potential risk factor for PR. Mechanistic studies have shown that IRGM/Irgm1 contributes to the formation and rupture of fragile plaques. This is partly mediated by the induction of macrophage apoptosis via the MAPK signaling pathway. IRGM may offer new strategies for early treatment of ACS.Translation viewOur findings indicate that IRGM/Irgm1 contributes to formation and rupture of vulnerable plaques. It suggests that IRGM may provide a new target for the early treatment of ACS.

Lead pollution has attracted significant attention over the years. However, research on the transfer of lead between urban atmospheric particles, soils, and plants remains rare. We measured lead concentrations and lead isotope ratios in total suspended particles (TSP), soil, and plants in an urban wetland in Beijing. The study period was September 2016-August 2017- covering all four seasons. The concentrations of lead in the atmospheric particles vary from 3.13 to 6.68 mg/m

Heavy metals in soil are in a high background state in Karst areas, and agricultural activities will affect the bioactivity of heavy metals. The heavy metal (Cd and Cr) bioactivity and their activation effects in rice-rape rotation lands in Karst areas were studied based on field experiments and laboratory analysis, and the influencing factors of heavy metal activity were analyzed based on the physical and chemical properties of soil. The results suggest that the residual fraction was the largest and the exchangeable fraction was the smallest for both Cr and Cd in rice-rape rotation lands in Karst areas. During the rice-rape rotation process, Cd and Cr tended to be released from the residual fraction and transformed into the other four fractions. The fractions with high bioactivity, including the exchangeable fraction and carbonate fraction, increased to different degrees. Rice-rape rotation could activate the activity of soil Cd and Cr in Karst areas. It is also revealed that the activity of soil Cd and Cr in Karst areas was closely associated with soil pH and electric potential (Eh). In the 0–20 cm soil layer, Cr showed a significant negative correlation with pH (r = −0.69, p &lt, 0.05), while both Cr and Cd showed significant negative correlations with Eh, and the correlation coefficients were −0.85 (p &lt, 0.01) and −0.83 (p &lt, 0.01), respectively. In the 20–40 cm soil layer, Cr showed significant negative correlations with Eh, and the correlation coefficient was −0.95 (p &lt, 0.01). No significant correlation between the activity of soil Cd and Cr and soil mechanical composition was observed. This study revealed that special attention should be paid to changes in pH and Eh in consideration of heavy metal activity in the rice-rape rotation process.

A facile approach to the fully substituted cyclopentenones involving an unprecedented benzofuran-ring-opening is described. The cleavage of a benzofuran endocyclic C2–O bond proceeded smoothly in the absence of any transition metal catalyst or highly reactive organometallic reagent. Such benzofuran-ring-opening is delicately incorporated into an acid-catalyzed cascade process, orchestrating a novel synthetic strategy for complex cyclopentenones with excellent yields and diastereoselectivities.

Protecting soil from Pb contamination has been a programme for a long time in China. However, research on lead pollution in wetlands remains rare. To understand the characteristics of Pb pollution in Beijing and the sources of contamination of different soil samples in wetlands, we collected samples during all four seasons from two soil horizons and analyzed their Pb concentrations and Pb isotope ratios. The average concentrations of Pb varied from 65.44 mg/kg in spring to 106.11 mg/kg in winter. Concentrations in autumn were significantly lower than those in spring and summer and were notably different between A and B Horizons (59.42 and 71.47 mg/kg, respectively). The Pb isotopic compositions show that Pb pollution results from a mixing of geogenic and anthropogenic materials. The ratios of

The content of heavy metals in the soil in Guizhou Province, which is a high-risk area for heavy metal exposure, is significantly higher than that in other areas in China. Therefore, the objective of this study was to evaluate the ability of CaCO3 and clay to accumulate heavy metals in topsoil sample collected from Lixisol using the method of indoor simulation. The results showed that the contents of Cu, Zn, Cd, Cr, Pb, Hg and As in the soil sample were 10.8 mg/kg, 125 mg/kg, 0.489 mg/kg, 23.5 mg/kg, 22.7 mg/kg, 58.3 mg/kg and 45.4 mg/kg, respectively. The soil pH values increased with the CaCO3 concentration in the soil, and the fluctuation of the soil pH values was weak after the CaCO3 concentrations reached 100 g/kg. The adsorption capacity of lime soil increased by approximately 10 mg/kg on average, and the desorption capacity decreased by approximately 300 mg/kg on average. The desorption of all heavy metals in this study did not change with increasing clay content. Pseudo-second-order kinetics were more suitable for describing the adsorption kinetics of heavy metals on the soil material, as evidenced by the higher R2 value. The Freundlich model can better describe the adsorption process of As on lime soil. The process of As, Cr, Cd and Hg adsorption on the soil sample was spontaneous and entropy-driven. Additionally, the process of Cu and Pb adsorption on the soil materials was spontaneous and enthalpy-driven. Generally, the adsorption and desorption of heavy metals in polluted soil increased and decreased, respectively, with increasing CaCO3 content. The effect of calcium carbonate on the accumulation of heavy metals in soil was greater than that of clay. In summary, CaCO3 and pH values in soil can be appropriately added in several areas polluted by heavy metals to enhance the crop yield and reduce the adsorption of heavy metals in soils.

To investigate the characteristics of pulmonary artery distensibility (PAD) in patients with acute pulmonary embolism (APE) and to assess the correlation of PAD with APE severity and right ventricular function. A total of 33 patients who underwent retrospective electrocardiogram (ECG)-gated computed tomography pulmonary angiography (CTPA) with a definite diagnosis of APE were included in the study. According to APE severity, the patients were divided into severe (SPE) and non-severe (NSPE) groups. Data from a control group without APE matching the basic demographics of the APE patients were collected. Pulmonary artery distensibility (PAD) and right ventricular function parameters were compared among the 3 groups, their relationships were investigated, and receiver operating characteristic (ROC) curves were used to determine the sensitivity and specificity of the above parameters for the diagnosis of APE severity. The PAD values of the control, NSPE, and SPE groups were (7.877 ± 2.637) × 10-3 mm/Hg, (6.050 ± 2.011) × 10-3 mm/Hg, (4.321 ± 1.717) × 10-3 mm/Hg, respectively (P

Hydrosols are byproducts produced by steam distillation of aromatic plant materials. Previous studies reported hydrosols owned effectively inhibitory effects on microbials, but few focused on the effects in reducing enzymatic browning of fresh-cut products. Here, application of citronella hydrosol (CH) and rose hydrosol (RH) obviously reduced values of L*, a* and b* in surfaces of fresh-cut taros, suggesting these hydrosols could reduce browning severity. About 500 ml/L of RH and CH reduced total phenol contents, and activities of phenylalanine ammonia lyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO), suggesting hydrosols suppressed browning development by reducing PAL, POD and PPO activities. Studies reported terpenoids had potential inhibition on PPO activity. Chemical composition analysis showed that RH and CH extracts contained abundant terpenoids. These imply that terpenoids contained in two hydrosols might have contributed to the reduction of enzyme activity. This study indicates that hydrosols might be promising natural anti-browning agents for fresh-cut foods. PRACTICAL APPLICATIONS: Hydrosols are the byproducts of essential oil from steam distillation. The work described here shows that application of citronella and rose hydrosols significantly reduced the browning of fresh-cut taros. Moreover, aromatic hydrosols also present inhibitory activity against microorganisms and are generally considered safe for human health. These suggested that aromatic hydrosols are the natural and useful anti-browning agents to preserve the quality of fresh cut foods, and can be well integrated into industrial procedures.

Coastal wetlands are ecologically and economically important; however, they are currently faced with fragmentation and loss. Plants are a fundamental element of wetlands and previous researches have focused on wetland plant connectivity; however, these researches have been conducted at the landscape but not species level. Here, given that tidal flats are important areas in coastal wetlands, we investigated the connectivity characteristics of typical plant species and environmental factors in different wetland regions influenced by various tidal conditions to reveal vegetation connectivity and its relationship with environmental factors on a small-patch scale. We found that tides negatively affect plant connectivity because both the Tamarix chinensis and Suaeda salsa have the highest connectivity on river banks, which are not influenced by tides. Of two tidal regions, different tides conditions have different influence on two plant species. T. chinensis had higher connectivity in the supratidal zone, whereas S. salsa had higher connectivity in the intertidal zone. Besides, the soil water content and soil salinity were significantly different in the three regions, but the soil total nitrogen and phosphorous were not. Soil water content and soil salinity were two factors that significantly affected plant connectivity. Specifically, soil water content positively affected the connectivity of T. chinensis and S. salsa, whereas soil salinity negatively affected the connectivity of T. chinensis. Taken together, these results indicate that tidal conditions affect plant connectivity on a small-patch scale. River banks and supratidal zone are beneficial for the recovery and growth of T. chinensis, intertidal zone and river banks are more conducive to the recovery and growth of S. salsa. Based on the above research, this study provides insights that could be applied to vegetation restoration in coastal wetlands.

Today, particulate-matter (PM) pollution has become one of the most severe air-pollution problems. As the most commonly used method in daily life, phytoremediation can use plant organs (such as leaves) as biological filters for pollutants to repair the atmosphere. At the same time, rainfall can remove PM from plant-leaf surfaces and enable them to adsorb PM again. By simulating natural rainfall, the rainfall characteristics are quantified as rainfall intensity and rainfall duration, and we use the washout-weighing method to obtain the amount of PM removed from the leaf surface. Then, use a scanner to scan the leaves after rain to get their images, and use Image J software to process the images to obtain leaf area. Finally, the amount of PM removed by rain per unit leaf area can be calculated. It will be used to explore the impact of different rainfall intensity and duration on the removal of PM from the leaf surface of wetland plants. The results showed that under three rainfall intensities used in this experiment, the removal of PM from plant-leaf surfaces all increased with an increase in rainfall duration. When the particle size is 10-100-μm, and the rainfall intensity is 30 mm/h, the removal amount of plant particles tested in this experiment is the largest. With increased rainfall duration, the removal of PM from plant-leaf surfaces increased sharply at first, then slowly, and finally tended to be stable. The removal efficiency of PM on the blade surface is most apparent at the early stage of rainfall, and then gradually weakens. Among the four wetland plants tested in this experiment, in the range of 10-100-μm, the number of PM on the leaf surface of Scirpus validus is the largest, and the optimum rainfall intensity is 30 mm/h; in the range of 2.5–10-μm, the number of PM on the leaf surface of Typha orientalis is the largest, and the optimal rainfall intensity is 30 mm/h; in the range of 0.45–2.5-μm, the number of PM on the leaf surface of Iris wilsonii is the largest, and the optimal rainfall intensity is 15 mm/h. Wetland species with high particle accumulation capacity can provide references for vegetation restoration of degraded wetland plants and plant cultivation in constructed wetlands. At the same time, the best rainfall intensity and duration for removing particulate matter on the surface of plant leaves were obtained through experiments, which provided a reference for the design of automatic plant irrigation systems and dust removers in different scenarios.

Karst landforms are widely distributed in Guizhou Province, and the karst terrain is complex. To investigate the spatial distribution characteristics of soil organic carbon (SOC) in topsoil in different karst landforms, a total of 920 samples were taken from different karst landforms. The study areas, Puding, Xingyi, Guanling, Libo and Yinjiang in Guizhou Province, represent the karst plateau (KP), karst peak-cluster depression (KPCD), karst canyon (KC), karst virgin forest (KVF) and karst trough valley (KTV) landforms, respectively. The characteristics of the SOC contents in areas with different vegetation, land use and soil types under different karst landforms were analyzed. The dimensionality of the factors was reduced via principal component analysis, the relationships among SOC content and different factors were subjected to redundancy analysis, and the effects of the main impact factors on SOC were discussed. The results showed that there was a large discrepancy in the SOC contents in the topsoil layers among different types of karst landforms, the changes in the SOC content in the topsoil layer were highly variable, and the discrepancy in the upper soil layer was higher than that in the lower soil layer. The SOC contents in the 0&ndash, 50 cm topsoil layers in different karst landforms were between 7.76 and 38.29 g&middot, kg&minus, 1, the SOC content gradually decreased with increasing soil depth, and the descending order of the SOC contents in different karst landforms was KTV &gt, KVF &gt, KC &gt, KPCD &gt, KP.

An efficient base-promoted tandem reaction between vinyl 1,1-dichlorides and secondary sulfonamides with ynamide as the key intermediate is described. This method provides a facile approach to (

The applicability of the ordinary kriging method for estimating the soil organic carbon (SOC) stored in karst regions was investigated. A total of 23,536 soil samples were analysed from 2755 soil profiles collected using a grid-based sampling method in a typical small karst basin of western Guizhou in Southwest China. Corrections for the gravel content and rock exposure rate were applied to the GIS-based spatial interpolation and simulation and were compared with the same approach with the addition of soil profiles. With the addition of the soil profile data, the SOC stored in the karst catchment was accurately calculated as follows: 1.48 × 108 kg at a depth of 10 cm, 2.65 × 108 kg at 20 cm, 3.43 × 108 kg at 30 cm, and 5.39 × 108 kg at 100 cm. With the interpolation that was corrected for the rock exposure rate and soil depth, the resulting carbon storage estimation was 1.14–1.19 times higher than the most accurate estimate (that with the soil profiles), with an error rate of 114%–119%. Since the conventional geostatistical method failed to accurately fit the data, including the spatial distribution, micro-geomorphic features, rock exposure rate, and depth of the soil patches in the highly sloped exposed bedrock, must be used to correct the estimation of the SOC storage and organic carbon density in karst areas. Keywords: Correction, Karst, Organic carbon storage, GIS spatial interpolation simulation, Applicability

Using the grid‐based sampling method, 2755 soil profiles consisting of 22,057 soil samples were sampled and analyzed to study the spatial distribution and storage of soil organic carbon (SOC) in the Houzhai River Basin in Guizhou Province, a typical karst region in southwestern China. The results suggest that the total levels of SOC stored in the 0–10, 0–20, 0–30, and 0–100 cm soil layers of the Houzhai River Basin are approximately 1.48 × 108, 2.65 × 108, 3.44 × 108, and 5.39 × 108 kg C, respectively. SOC content and soil bulk density levels were found to vary depending on the land use. In the 0–50 cm soil layer, forest SOC content levels (including arbor forests, arbor–shrub mixed forests, shrubland, and shrub grassland) are generally higher than those of uncultivated land, followed by grassland and cropland (including paddy fields, arid land, sloping cropland, and abandoned cropland), gardens, and orchard. It is believed that land use is a vital factor directly affecting carbon storage patterns in the study area. Soil thickness, rock outcrop, and slope gradients are the main factors in arrangement of land use by local governments and peasants. This study has established a feasible method for assessment of SOC stock in karst mountainous areas. The findings of this study are applicable to other karst mountainous regions globally.

A convenient and straightforward strategy for the synthesis of 2,3-disubstituted and 2,3,5-trisubstituted furans via a base-promoted domino reaction of β-keto compounds with vinyl dichlorides is described. This transition-metal-free approach proceeds under operationally simple reaction conditions featuring easily available starting materials, a broad substrate scope, and good functional group tolerance.

With the increasing complexity and variety of production systems, more attention is being paid to preventive replacement on multicomponent systems. Each component is non-identical and has its own degradation process. In this paper, we propose a criticality importance-based spare ordering policy for a complex system, which consists of multiple series-parallel degrading components. Replacement action is triggered whenever the system reliability drops below a lower threshold and spares for replacement are available. Our policy mainly consists of two steps: (1) determine which components to be replaced; (2) determine when to order spares for components selected. In step 1, when the replacement action is triggered, we select components that most need to be replaced within the system in accordance with the optimum ranking of components until the system meets an upper reliability threshold. In step 2, a spare ordering policy for components selected is made and the optimal spare ordering time is obtained by minimizing the expected replacement cost during the once replacement cycle. Finally, a numerical example is given to illustrate the proposed multi-spare ordering policy. Moreover, the proposed policy is of significance for safety-critical systems such as substation automation system, bridge system, nuclear power plants and aerospace equipment.

The present article reports an assessment of afforestation potential and anticipation of carbon sequestration in the Houzhai River Basin in Guizhou Province in southwestern China. Total of 2755 soil profiles consisting of 22,057 soil samples were collected according to a grid-sampling method at a 150 m scale in the Houzhai River basin, and the SOC contents in soil samples were analyzed using a titration method. General information regarding the geographic characteristics of each sampling grid was recorded in the field. The results indicate that land use in the Houzhai River Basin is very complex. Land use status and land use change in the study area were closely associated with local geographic characteristics and variations in economic structures. There were approximately 15.26 km2 of land that could or should be rearranged as afforestation land in the Houzhai River Basin. The increased SOC storage (0.00–1.00 m soil horizon) would be up to 5.48 × 104 Mg, 6.42 × 104 Mg, 4.77 × 104 Mg and 3.18 × 104 Mg when all of the calculated lands became shrub-grass lands, shrub lands, arbor-shrub forest lands and arbor forest lands, respectively. The increased SOC percentages would be 52.16%, 61.13%, 45.39% and 30.32%, respectively, in comparison with the present SOC storage in these lands.