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Objective: To explore the effects of Panax ginseng fruit juice concentrate on immune function in immunocompromised mice. Methods: Totally 72 specific pathogen-free (SPF) C57BL/6J male mice were randomly divided into six groups (n = 12): blank, model, and low-, medium- and high-dose Panax ginseng fruit juice concentrate (83, 166, 249 and 332 mg/kg mb). The model and Panax ginseng fruit juice concentrate groups were injected intraperitoneally with 40 mg/kg mb cyclophosphamide on a daily basis for 10 days while the blank group was intraperitoneally injected with the same amount of phosphate buffered saline (PBS). Afterwards, the mice in the Panax ginseng fruit juice concentrate groups were intragastrically administrated with different dosage of Panax ginseng fruit juice concentrate at a volume of 20 mL/kg mb, and those in the blank and model groups were gavaged with the same volume of distilled water for 15 days. Then, body, spleen and thymus mass, white blood cell count, the number of lymphocyte subsets, cytokine expression levels, and nuclear transcription factor expression levels in immune cells were measured. Results: Panax ginseng fruit juice concentrate could improve the spleen mass/index (spleen/body mass ratio) in immunocompromised mice, increase the number of peripheral blood cells and the number of lymphocytes in immune organs, promote the expression of cytokines interleukin (IL)-2, IL-4 and IL-17, inhibit the expression of transforming growth factor (TGF)-β in immunocompromised mice and partially restore the RNA expression of T-box expressed in T cells (T-bet) and forkhead box protein 3 (Foxp3) (P < 0.05), and the effect of Panax ginseng fruit juice concentrate at a dose of 249 mg/kg mb was the most significant. However, Panax ginseng fruit juice concentrate had no significant effect on restoring the body mass or thymus mass of immunocompromised mice. Conclusion: Panax ginseng fruit juice concentrate can enhance immune function in immunocompromised mice.

Flash flood disasters are one of the major natural disasters in the world, and rapid and accurate early identification of flash flood disasters is the key to preventing and controlling them. In recent years, computer and spatial information technology development has promoted the advancement of early identification technology for flash floods. However, previous research has mainly focused on the impact of 'water' and neglected the impact of 'sediment' deposition on the rise of water levels. To gain a more comprehensive understanding of flash floods and improve the accuracy of early identification, this article first uses bibliometric methods to review the spatiotemporal distribution, internal relationships, and research hotspots of literature in this field over the past 42 years. Then, the research practice of considering the impact of sediment on the early identification of flash floods was introduced from three aspects: mechanism, model, and uncertainty. Finally, the existing problems in current research were discussed, and future research directions were proposed. The research results have shown that the number of publications in this field has been increasing yearly and will continue to increase, but the cooperation between authors is not close. The coupling effect between sediment replenishment and floods cannot be ignored. Taking into account multiple uncertainties can greatly improve recognition accuracy. This study can provide a panoramic literature perspective and practical research experience for relevant researchers and decision-makers and support further improving flash flood prevention and control capabilities. [ABSTRACT FROM AUTHOR]

Aerators with sharp lateral enlargements and bottom drops generally cause adverse effects in spillway tunnels with a mild base slope, including serious cavity back flow and water wings striking the tunnel roof. Taking RM Hydropower Station's spillway tunnel as its example, this paper proposes a new type of combined aerator characterized by a "variable base slope" longitudinally and a transverse "sharp enlargement plus straight section." This not only increases cavity stability, resulting in more effective aeration, but also inhibits the development of water wings, contributing to an improved pattern of water flow. In addition, this paper systematically explores the influence of the flip bucket (drop), gently sloping section, and steeply sloping section of the "variable base slope" aerator upon the aerated cavity and summarizes the rules according to which the sharp lateral enlargement and diffusion angle influence the formation of water wings. This offers technical solutions, with theoretical support, for the design of aerators in spillway tunnels with a mild base slope. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the mechanism of sustainable biodegradation of long-alkanes with moderate pre-oxidation in soil. Moderate pre-oxidation was performed with two consecutive doses of 1.35 mL 30% of H2O2 (225 mM) in two soil. After moderate pre-oxidation, the experiment of sustainable biodegradation of long-alkanes during 80 d was conducted. Then, long-alkanes relative activity coefficient (K), NH4+-N allocation (G) and the performance of hydrocarbon degraders (E) was calculated. Long-alkanes were sustainably biodegraded with moderate pre-oxidation (1765 mg/kg, 2438 mg/kg and 2672 mg/kg). Long-alkanes biodegradation (8723 mg/kg) with moderate pre-oxidation was 2.5 folds of excessive pre-oxidation. The average increment in long-alkanes biodegradation with moderate pre-oxidation was 30–38% as K values improved (0.28–0.48). The bacterial destruction D decreased to 14–17% and hydrocarbon degraders activity increased to 0.065 mol CO2/kg with moderate pre-oxidation. Basidiomycota and Acinetobacter sp. showed high tolerance with moderate pre-oxidation and remained dominant strains throughout the bioremediation. NH4+-N consumption played an essential role as nutrients in growth of hydrocarbon degraders (Basidiomycota and Acinetobacter sp.). Then, high and sustained E was achieved with decreased D and elevated hydrocarbon degraders activity, resulting in high K. So, long-alkanes sustainably increasing biodegraded under high E assisted with elevated G with moderate pre-oxidation. [ABSTRACT FROM AUTHOR]

A high rate of elemental sulfur (S0) accumulation from sulfide-containing wastewater has great significance in terms of resource recovery and pollution control. This experimental study used Thiobacillus denitrificans and denitrifying bacteria incorporated with signal molecules (C6 and OHHL) for simultaneous sulfide (S2–) and nitrate (NO3–) removal in synthetic wastewater. Also, the effects on S0 accumulation due to changes in organic matter composition and bacteria proportion through signal molecules were analyzed. The 99.0% of S2– removal and 99.3% of NO3– was achieved with 66% of S0 accumulation under the active S2– removal group. The S0 accumulation, S2– and NO3– removal mainly occurred in 0–48 h. The S0 accumulation in the active S2– removal group was 2.0-6.3 times higher than the inactive S2– removal groups. In addition, S0/SO42- ratio exhibited that S0 conversion almost linearly increased with reaction time under the active S2– removal group. The proportion of Thiobacillus denitrificans and H+ consumption showed a positive correlation with S0 accumulation. However, a very high or low ratio of H+/S0 is not suitable for S0 accumulation. The signal molecules greatly increased the concentration of protein-I and protein-II, which resulted in the high proportion of Thiobacillus denitrificans. Therefore, high S0 accumulation was achieved as Thiobacillus denitrificans regulated the H+ consumption and electron transfer rate and provided suppressed oxygen environment. This technology is cost-effective and commercially applicable for recovering S0 from wastewater. [ABSTRACT FROM AUTHOR]

In recent years, RS and GIS technologies have played an increasingly important role in various aspects of rainfall induced landslide research. In order to systematically understand their application situation, this paper extensively used various visualization analysis technologies for in-depth analysis of 1,161 documents collected by the WOS data platform in the past 27 years by combining quantitative and qualitative methods. Then, this article focuses on sub domain analysis from four aspects: landslide detection and monitoring, prediction models, sensitivity mapping, and risk assessment. The study found that the number of literature in this field has steadily increased and is expected to continue to rise. This literature review has attracted widespread attention from the academic community, but it is challenging to meet research needs. Frequent and effective cooperation between countries, institutions, and authors is very beneficial for promoting progress in this field. The future development direction is a new intelligent hybrid model that integrates multiple research methods. This study can provide researchers in this field with the core research force, hot topic evolution, and future development trends of future rainfall-induced landslides and contribute to landslide prevention and control decision-making and achieving the United Nations'sustainable development goals. [ABSTRACT FROM AUTHOR]

A flash flood disaster is one of the most destructive natural disasters. With the increase in extreme rainfall events, more and more areas will be threatened by flash floods. The flash flood susceptibility assessment is the basis of flash flood risk assessment and is also an important step in flash flood disaster management. Based on Citespace analysis tools, this study made a bibliometric and visualized analysis of 305 documents collected in the core collection of Web of Science in the past 15 years, including the analysis of the number of publications and citation frequency, influence analysis, keyword analysis, author co-citation analysis, and institutional co-operation analysis. This paper summarizes the current research status and future development trend of flash flood susceptibility assessment from five key research subfields, including assessment scale, assessment unit, assessment index, assessment model, and model assessment method, discusses the analysis of the application of remote sensing and GIS in flash flood susceptibility assessment, discusses the problems encountered in the current research of the five subfields, and provides suggestions for flash flood hazard control. [ABSTRACT FROM AUTHOR]

With the social and economic development in recent years, human activities have been more extensive and intensified. As a result, ecosystems are damaged to varying degrees, and regional ecological environments tend to be weaker. The socio-ecological system in Aba Prefecture, Western Sichuan Plateau, China, the researched area, also faces increasingly serious problems. To advance ecological civilization development in a coordinated way across the country, the national government and the competent authorities have launched a series of new strategies. Research on socio-ecological vulnerability, a major part of the ecosystem protection and restoration program, is provided with powerful spatial data observation and analysis tools thanks to the invention and development of remote sensing and geographic information system technologies. This study was based on the vulnerability scoping diagram (VSD) framework. Multi-source data such as digital elevation model (DEM), geographical data such as land use types, soil and geological disasters, remote sensing image data, meteorological data and social statistics data from 2005 to 2019 were used to construct the temporal social-ecosystem vulnerability evaluation index database of Aba Prefecture, Western Sichuan Plateau. The spatial principal component analysis (SPCA) is applied to evaluating the socio-ecological vulnerability and analyzing its spatial-temporal variation in Aba Prefecture, Western Sichuan Plateau. To probe into the driving effects of various impact factors on the socio-ecological vulnerability, the Geodetector is used to analyze the driving factors. The ordered weighted average (OWA) method is applied to the multi-scenario analysis of socio-ecological vulnerability in the researched area. The conclusions of this study are as follows: (1) from 2005 to 2019, the spatial distribution characteristics of exposure and sensitivity in Aba Prefecture were higher in the southeast and lower in the northwest, and the overall spatial distribution characteristics of socio-ecological system vulnerability showed that the degree of vulnerability increased from the north to the southeast. (2) Extreme natural climate conditions play a leading role in the driving of socio-ecosystem vulnerability, followed by human production activities and geological hazards. (3) The degree of social-ecosystem vulnerability in Aba Prefecture will increase with the increase of decision risk coefficient. The results of social-ecosystem vulnerability under the status quo scenario are similar to those in 2010 and 2019, indicating that the selected evaluation factors can reflect the actual social-ecosystem vulnerability. In the sustainable guided scenario and the unsustainable guided scenario, the proportion of the area of the social-ecosystem severe vulnerability level was at the minimum value and the maximum value, respectively. [ABSTRACT FROM AUTHOR]

Landslide prediction is one of the complicated topics recognized by the global scientific community. The research on landslide susceptibility prediction is vitally important to mitigate and prevent landslide disasters. The instability and complexity of the landslide system can cause uncertainty in the prediction process and results. Although there are many types of models for landslide susceptibility prediction, they still do not have a unified theoretical basis or accuracy test standard. In the past, models were mainly subjectively selected and determined by researchers, but the selection of models based on subjective experience often led to more significant uncertainty in the prediction process and results. To improve the universality of the model and the reliability of the prediction accuracy, it is urgent to systematically summarize and analyze the performance of different models to reduce the impact of uncertain factors on the prediction results. For this purpose, this paper made extensive use of document analysis and data mining tools for the bibliometric and knowledge mapping analysis of 600 documents collected by two data platforms, Web of Science and Scopus, in the past 40 years. This study focused on the uncertainty analysis of four key research subfields (namely disaster-causing factors, prediction units, model space data sets, and prediction models), systematically summarized the difficulties and hotspots in the development of various landslide prediction models, discussed the main problems encountered in these four subfields, and put forward some suggestions to provide references for further improving the prediction accuracy of landslide disaster susceptibility. [ABSTRACT FROM AUTHOR]

Global climate changes have a great impact on terrestrial ecosystems. Vegetation is an important component of ecosystems, and the impact of climate changes on ecosystems can be determined by studying vegetation phenology. Vegetation phenology refers to the phenomenon of periodic changes in plants, such as germination, flowering and defoliation, with the seasonal change of climate during the annual growth cycle, and it is considered to be one of the most efficient indicators to monitor climate changes. This study collected the global land surface satellite leaf area index (GLASS LAI) products, meteorological data sets and other auxiliary data in the Three-River headwaters region from 2001 to 2018; rebuilt the vegetation LAI annual growth curve by using the asymmetric Gaussian (A-G) fitting method and extracted the three vegetation phenological data (including Start of Growing Season (SOS), End of Growing Season (EOS) and Length of Growing Season (LOS)) by the maximum slope method. In addition, it also integrated Sen's trend analysis method and the Mann-Kendall test method to explore the temporal and spatial variation trends of vegetation phenology and explored the relationship between vegetation phenology and meteorological factors through a partial correlation analysis and multiple linear regression models. The results of this study showed that: (1) the SOS of vegetation in the Three-River headwaters region is concentrated between the beginning and the end of May, with an interannual change rate of −0.14 d/a. The EOS of vegetation is concentrated between the beginning and the middle of October, with an interannual change rate of 0.02 d/a. The LOS of vegetation is concentrated between 4 and 5 months, with an interannual change rate of 0.21 d/a. (2) Through the comparison and verification with the vegetation phenological data observed at the stations, it was found that the precision of the vegetation phonology extracted by the A-G method and the maximum slope method based on GLASS LAI data is higher (MAE is 7.6 d, RMSE is 8.4 d) and slightly better than the vegetation phenological data (MAE is 9.9 d, RMSE is 10.9 d) extracted based on the moderate resolution imaging spectroradiometer normalized difference vegetation index (MODIS NDVI) product. (3) The correlation between the SOS of vegetation and the average temperature in March–May is the strongest. The SOS of vegetation is advanced by 1.97 days for every 1 °C increase in the average temperature in March–May; the correlation between the EOS of vegetation and the cumulative sunshine duration in August–October is the strongest. The EOS of vegetation is advanced by 0.07 days for every 10-h increase in the cumulative sunshine duration in August–October. [ABSTRACT FROM AUTHOR]

An improper design of an air vent will not only cause waste of resources but also seriously threaten the safety of the spillway tunnel. The present study analyzes the effects of the area and position of the air vent on the air supply, using the volume of fluid method with the k–ε turbulence model. The air speed in the air vent will decrease with an increase in the area, but the quantity of air supplied will increase. When the area of air vents is equal to the tunnel residual, the air supply capacity of the air vent reaches the maximum. A relationship between the quantity of air supplied and the area of the air vent is put forward, and the error with the prototype observation result is about 10%. The distribution of negative pressure in the tunnel may be improved by arranging the air vent in a proper position; the quantity of air supplied also decreases as the distance between the air vent and the pressurized conduit increases. In general, it is more advantageous to position the air vent upstream. These results provide a reference for the air ventilation design in hydraulic engineering. [ABSTRACT FROM AUTHOR]

Flash flood is one of the extremely destructive natural disasters in the world. In recent years, extreme rainfall events caused by global climate change have increased, and flash flood disasters are becoming the main types of natural disasters in the world. Due to the characteristics of strong suddenness, complex disaster-causing factors, great difficulty in prediction and forecast, and the lack of historical data, it is difficult to effectively prevent and control flash flood disaster. The early identification technology of flash floods is not only the basis of flash flood disaster prediction and early warning, but also an effective means of flash flood prevention and control. The paper makes a meta-analysis and visual analysis of 475 documents collected by the Web of Science Document Platform in the past 31 years by comprehensively using Citespace, Vosviewer, Origin, etc. We systematically summarize the research progress and development trend of early identification technology of flash flood disasters from five key research subfields: (1) precipitation, (2) sediment, (3) sensitivity analysis, (4) risk assessment, (5) uncertainty analysis. In addition, we analyze and discuss the main problems encountered in the current research of several subfields and put forward some suggestions to provide references for the prevention and control of flash flood disasters. [ABSTRACT FROM AUTHOR]

After the "5·12" Wenchuan earthquake in 2008, collapses and landslides have occurred continuously, resulting in the accumulation of a large quantity of loose sediment on slopes or in gullies, providing rich material source reserves for the occurrence of debris flow and flash flood disasters. Therefore, it is of great significance to build a collapse and landslide susceptibility evaluation model in Wenchuan County for local disaster prevention and mitigation. Taking Wenchuan County as the research object and according to the data of 1081 historical collapse and landslide disaster points, as well as the natural environment, this paper first selects six categories of environmental factors (13 environmental factors in total) including topography (slope, aspect, curvature, terrain relief, TWI), geological structure (lithology, soil type, distance to fault), meteorology and hydrology (rainfall, distance to river), seismic impact (PGA), ecological impact (NDVI), and impact of human activity (land use). It then builds three single models (LR, SVM, RF) and three CF-based hybrid models (CF-LR, CF-SVM, CF-RF), and makes a comparative analysis of the accuracy and reliability of the models, thereby obtaining the optimal model in the research area. Finally, this study discusses the contribution of environmental factors to the collapse and the landslide susceptibility prediction of the optimal model. The research results show that (1) the areas prone to extremely high collapse and landslide predicted by the six models (LR, CF-LR, SVM, CF-SVM, RF and CF-RF) have an area of 730.595 km2, 377.521 km2, 361.772 km2, 372.979 km2, 318.631 km2, and 306.51 km2, respectively, and the frequency ratio precision of collapses and landslides is 0.916, 0.938, 0.955, 0.956, 0.972, and 0.984, respectively; (2) the ranking of the comprehensive index based on the confusion matrix is CF-RF>RF>CF-SVM>CF-LR>SVM>LR and the ranking of the AUC value is CF-RF>RF>CF-SVM>CF-LR>SVM>LR. To a certain extent, the coupling models can improve precision more over the single models. The CF-RF model ranks the highest in all indexes, with a POA value of 257.046 and an AUC value of 0.946; (3) rainfall, soil type, and distance to river are the three most important environmental factors, accounting for 24.216%, 22.309%, and 11.41%, respectively. Therefore, it is necessary to strengthen the monitoring of mountains and rock masses close to rivers in case of rainstorms in Wenchuan county and other similar areas prone to post-earthquake landslides. [ABSTRACT FROM AUTHOR]

On 8 August 2017, Jiuzhaigou earthquake, magnitude 7.0, hit northern Sichuan, China. As the earthquake-stricken area is located in the mountainous region with forest and low residential density, the main damage is to vegetation and roads by earthquake-triggered landslides. In this study, the core area of Jiuzhaigou natural reserve, one of the highest seismic intensity zones, is selected. The landslides are extracted by examining vegetation changes from the preearthquake and postearthquake images using the Normalized Difference Vegetation Index (NDVI) and are verified by slope. As most road damage in the mountainous region could be attributed to the landslides nearby, the impacts of landslide on road are studied based on spatial analysis and are used to infer occluded road damage. Then, a knowledge-based method for postearthquake road detection and road capacity assessment from preearthquake road data and postearthquake high-resolution remote sensing imagery is proposed, as well as the quantitative road capacity assessment indicators to classify the road grades. This method is evaluated using the Beijing-2 (BJ-2) satellite images over the study area acquired on 28 April and 9 August. Compared with visual interpretation results, the extraction accuracy reached 90% for landslides and 85% for postearthquake roads, indicating that the approaches are effective and promising for quick response to devastating earthquake in similar circumstances. [ABSTRACT FROM AUTHOR]

The experimental study investigates the takeoff characteristics of lower jet trajectory from the dovetail-shaped flip bucket under different inlet conditions. The experiment analyzes the influences of velocity and water depth on lower takeoff characteristics, especially the variation of takeoff angle of lower jet trajectory. The following items are addressed: 1) relationship between takeoff angle of lower jet trajectory and inlet velocity as well as inlet water depth; 2) characteristics of the takeoff angle as a function of changes of inlet Fr0; 3) the empirical formulas for calculating takeoff angle of lower jet trajectory. The results indicate that the effects of inlet conditions are significant on lower takeoff characteristics. Additionally, with the established empirical formulas, the calculated values of horizontal distance of lower nappe profile are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

In this study, novel semiinterpenetrating polymer networks (semi‐IPNs) superabsorbent resins with slow‐release fertilizer (CSC‐g‐AA/APP, CSC‐g‐AA/PVA‐APP), based on corn straw cellulose polymer and linear polyvinyl alcohol (PVA), were prepared by solution polymerization. The nitric acid‐aqueous solution method was adopted to extract cellulose from corn straw. Ammonium polyphosphate (APP) was introduced to supply nitrogen and phosphorus nutrients. The prepared materials were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Moreover, the water absorbency and the slow‐release performance of CSC‐g‐AA/APP and CSC‐g‐AA/PVA‐APP were studied. The results indicated that the two superabsorbent resins exhibited excellent water absorbency of 262.8 and 303.2 g/g in distilled water, enhanced the water‐holding capacity of soil, and also released nutrients slowly. The cumulative N and P release rates of CSC‐g‐AA/PVA‐APP were 64.47 and 53.53% after 25 days in soil, which were lower than those of CSC‐g‐AA/APP. The addition of these products into soil significantly reduced the leaching losses of nutrients. Therefore, it can be concluded that the superabsorbent resins with water‐retaining and slow‐release properties, low production costs, and environment‐friendly characteristics, have great potential for applications in agricultural production. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48951. [ABSTRACT FROM AUTHOR]

Abstract To date, the connection between inorganic mercury (Hg) and social behavior remains incompletely understood. The aim of this study was to investigate the influence of maternal autoimmunity by inorganic Hg (Hg2+) exposure on social behavior of offspring. Wild-type (WT) and immunoglobulin deficient (Ig−/−) B10.S dams fertilized by male WT B10.S or SJL mice were treated with 50 μM Hg chloride (HgCl 2). Non-pregnant female WT B10.S mice were used to investigate factors regulating HgCl 2 -induced autoimmunity to brain. HgCl 2 selectively impaired social behavior in male offspring, but not female offspring from WT B10.S dams × male SJL, in that only male offspring displayed reduced time distribution with the stranger mouse, decreased sniffing to the stranger mouse and increased self-grooming. HgCl 2 did not disrupt social behavior of male or female offspring from WT B10.S dams × male WT B10.S or Ig−/− B10.S dams × male SJL. The offspring from WT and Ig−/− B10.S dams × male SJL had equivalent autoimmunity to brain antigens during HgCl 2 exposure, indicating that maternal, but not offspring-derived anti-brain antibodies (Ab) impaired social behavior of the offspring. Non-pregnant WT B10.S mice treated with HgCl 2 had increased anti-brain Ab dependent on increase in CD4 T cell activation and IFNγ signaling to macrophages. IFNγ interaction with macrophages drove B cells and plasma cells to produce IgG. Therefore, HgCl 2 selectively impaired social behavior in males with certain genetic background via maternally derived anti-brain Ab production, thus providing a novel insight into our current understanding of Hg toxicity. Highlights • HgCl 2 impairs social behavior in male offspring of B10.S dams × male SJL mice. • HgCl 2 -impaird social behavior depends on maternal anti-brain Ab production. • HgCl 2 -induced anti-brain Ab requires increased CD4 T cell activation and IFNγ. • IFNγ acts on macrophages to drive anti-brain Ab production during HgCl 2 exposure. [ABSTRACT FROM AUTHOR]

Gold nanoclusters (AuNCs) are one of metal nanoclusters, which play a pivotal role in the recent advances in the research of fluorescent probes for their fluorescence effect. They are favored by most researchers due to their strong stability in fluorescence and adjustability in fluorescence wavelength when compared to traditional organic fluorescent dyes. In this review, we introduce various synthesis strategies of gold-nanocluster-based fluorescent probes and summarize their application for environmental analysis and biological sensing. The use of gold-nanocluster-based fluorescent probes for the analysis of heavy metals and inorganic and organic pollutants is covered in the environmental analysis while biological labeling, imaging, and detection are presented in biological sensing. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal that impairs the development of hematopoietic stem cells (HSCs) in mice, yet the mechanism of how Cd influences HSC remains elusive. Herein, we show that Cd activated non-canonical Wnt signaling pathway to impair HSC function in mice. After exposure to 10 ppm Cd chloride (CdCl2) via drinking water for 3 months, C57BL/6 mice displayed aberrant HSC function, in that HSC from Cd-treated mice were less efficient in rescue of lethally irradiated hosts and less competitive under mixed chimeric condition. Further analyses indicated that the small GTPase cdc42 was activated and its distribution pattern was depolarized in HSC by Cd exposure, and inhibition of cdc42 by casin, a selective chemical inhibitor, recovered the HSC capacity in rescue assay and their potential for lymphopoiesis under competitive mixed chimeric assay. Cd interaction with HSC was sufficient to promote noncanonical Wnt signaling pathway, but not canonical Wnt signaling pathway, to drive cdc42 activation and further increase the expression of C/EBPα and decrease the expression of Hhex. Moreover, Cd-induced activation of non-canonical Wnt signaling pathway in HSC did not persist long-termly in the presence of a normal niche without Cd, in that the elevated non-canonical Wnt signaling by Cd was diminished in HSC in the BM of normal recipients receiving purified HSC from Cd-treated mice after 6 months posttransplantation. Taken together, our study suggests that Cd activates cdc42 of noncanonical Wnt signaling pathway to impair HSC function, a previously unknown mechanism for Cd toxicity on HSC. [ABSTRACT FROM AUTHOR]

Phosphorus (P) loss from arable sloping land due to water erosion causes off-site environment pollution in the Three Gorges area in China. This study aims to estimate the effects of agricultural practices on the reduction of P losses during water erosion processes under natural precipitation conditions: contour culturing with organic matter addition (CT + OM), contour culturing with wheat straw mulching (CT + SM), contour culturing with straw mulching and organic matter addition (CT + OM + SM) and conventional downslope culturing framework as a control (CK). Results demonstrated that CT + OM + SM could viably diminish runoff, sediment yields and P losses from arable sloping land. Compared with CK, CT + OM, CT + SM and CT + OM + SM lessened the surface runoff depths by 19%, 34% and 50%, respectively. A high curve number value induced a notable runoff potential from the plot. The surface-runoff-related total P (TP) loads for CK with yearly measures of 1·56 kg ha−1 were significantly higher than those for CT + OM, CT + SM and CT + OM + SM at 1·07, 0·77 and 0·51 kg ha−1 ( p < 0·05), respectively. With all things considered, the particulate P losses represented a significant division of TP losses, adding up to almost 80% in 2014 and 79% in 2015. The outcomes demonstrated that surface protection and organic matter addition are two of the greatest agricultural protection practices that lessen P losses in the surface runoff from sloping farmland by water erosion. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

High N fertilizer and flooding irrigation applied to rice in anthropogenic-alluvial soil often result in N leaching and low use efficiency of applied fertilizer N from the rice field in Ningxia irrigation region in the upper reaches of the Yellow River. Sound N management practices need to be established to improve N use efficiency while sustaining high grain yield levels and minimize fertilizer N loss to the environment. We investigated the effects of Nursery Box Total Fertilization technology (NBTF) on N leaching at different rice growing stages, N use efficiency and rice yield in 2010 and 2011. The four fertilizer N treatments were 300 kg N ha−1 (CU, Conventional treatment of urea at 300 kg N ha−1), 120 kg N ha−1 (NBTF120, NBTF treatment of controlled-release N fertilizer at 120 kg N ha−1), 80 kgN ha−1 (NBTF80, NBTF treatment of controlled-release N fertilizer at 80 kg N ha−1) and no N fertilizer application treatment (CK). The results showed that the NBTF120 treatment increased N use efficiency, maintained crop yields and substantially reduced N losses to the environment. Under the CU treatment, the rice yield was 9634 and 7098 kg ha−1, the N use efficiency was 31·6% and 34·8% and the leaching losses of TN were 44·51 and 39·89 kg ha−1; NH4+-N was 5·26 and 5·49 kg ha−1, and NO3−-N was 27·94 and 26·22 kg ha−1 during the rice whole growing period in 2010 and 2011, respectively. Compared with CU, NBTF120 significantly increased the N use efficiency and decreased the N losses from the paddy field. Under NBTF120, the N use efficiency was 56·3% and 51·4%, which was 24·7% and 16·6% higher than that of CU, and the conventional fertilizer application rate could be reduced by 60% without lowering the rice yield while decreasing the leaching losses of TN by 16·27 and 14·36 kg ha−1, NH4+-N by 0·90 and 1·84 kg ha−1, NO3−-N by 110·6 and 10·14 kg ha−1 in 2010 and 2011, respectively. Our results indicate that the CU treatment resulted in relatively high N leaching losses, and that alternative practice of NBTF which synchronized fertilizer application with crop demand substantially reduced these losses. We therefore suggest the NBTF120 be a fertilizer application alternative which leads to high food production but low environmental impact. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Chemical N input is essential for high rice yields. However, low recovery efficiency of chemical fertilizer N with flooding irrigation in the anthropogenic-alluvial soil resulted in N lost from the rice field in Ningxia Irrigation Region in the upper reaches of the Yellow River. With the technique of stable isotope 15N-traced urea, we conducted two years experiment to estimate the recovery efficiency and loss of applied chemical fertilizer in a rice field. The three fertilizer N treatments included 300kgha−1 (N300, the conventional application rate), 240kgha−1 (the optimized N application amount, N240) and no N fertilizer application treatment (CK). We estimated the recovery of 15N-labelled urea in grain, straw and root of rice and residues in soil profile. The 15N not accounted for in the plant and soil was presumably lost. The results showed that more efficient use of N fertilizer could allow current N application rates to reduce by 20%. This would still maintain crop yields while substantially reducing N losses to the environment. The high N fertilizer application increased the N uptake by rice derived from fertilizer, and the amount of N rice taken up from soil reduced correspondingly, which resulted in the higher N surplus in soil. Under the conventional irrigation and fertilizer management level, the recovery rate of 15N-labelled urea in rice–soil system was about 48–49%. The 15N-labelled fertilizer recovery in rice plant (N dff ) was 26–30%. In the paddy soil profiles of 0–90cm, the residual of 15N-labelled fertilizer in soil (N dfs) were 54–70kgha−1, and N residual rate in soils were 18–23%. The annual N loss from the rice field in the Irrigation Region was 28,865tons. The distribution of 15N abundance variability in different soil profile indicated that fertilizer N leached into the deep soil layers along with irrigation water as a result of continuous yearly rice planting. Optimization of nitrogen fertilizer can significantly reduce the amount of N residuals and N loss from the paddy field. Compared with N300, optimized nitrogen fertilizer application could decrease the loss of fertilizer N by 22–34kgha−1, and reduce the amount of N surplus by 26–33kgha−1 while the dry matter of rice increased 8–15% and N uptake by rice increased 2–6%. Considering the high food production and the minimum environmental threat, we should fully take into account the optimization application by reducing fertilizer N inputs. However, the interaction between irrigation management and N application rate on N use efficiency in alkaline anthropogenic-alluvial soil needs to be further studied. [Copyright &y& Elsevier]

Crop residue, the largest product of agricultural harvests, contains large amounts of assimilated carbon (C) and nutrients such as nitrogen (N), phosphorus (P), and potassium (P); these elements must be recycled for the sustainable development of agriculture. Crop residue management should serve a double function, both confronting global warming and food security by increasing carbon sequestration in agriculture and increasing grain yields. Historically, the North China Plain has experienced different crop residue management practices. While direct burning in the field remains an environmental problem in the region, crop residue amendment triggers benign cycling of C and nutrients in agriculture. Data showed that soil organic carbon (SOC) in topsoil increased by 0.174 to 1.74 g kg-1, with an average of 0.79 g kg-1 after wheat residue amendment collected from 35 sites in the North China Plain. The average increase in grain yield achieved by wheat residue amendment in the region is 260 kg ha-1 year-1 for wheat and 310 kg ha-1 year-1 for maize, for a total of 570 kg ha-1 year-1. At the same time, the available potassium (K2O), the available phosphorus (P2O5), and total nitrogen in soil increased, significantly or not. With the development of the economy, technology, and supporting policy, crop residue management can play an increasingly important role in sustainable agricultural development. [ABSTRACT FROM AUTHOR]

Flash floods are among the most dangerous natural disasters. As climate change and urbanization advance, an increasing number of people are at risk of flash floods. The application of remote sensing and geographic information system (GIS) technologies in the study of flash floods has increased significantly over the last 20 years. In this paper, more than 200 articles published in the last 20 years are summarized and analyzed. First, a visualization analysis of the literature is performed, including a keyword co-occurrence analysis, time zone chart analysis, keyword burst analysis, and literature co-citation analysis. Then, the application of remote sensing and GIS technologies to flash flood disasters is analyzed in terms of aspects such as flash flood forecasting, flash flood disaster impact assessments, flash flood susceptibility analyses, flash flood risk assessments, and the identification of flash flood disaster risk areas. Finally, the current research status is summarized, and the orientation of future research is also discussed. [ABSTRACT FROM AUTHOR]

• Few studies have analyzed the utilization of millet straw as raw materials in the preparation of superabsorbent resin. • The product had excellent water absorbency and slow-release property. • The product prepared by millet straw not only reduces production cost, but also promote plant growth. • Application of the fertilizer could achieve the goal of straw return to soil. To enhance utilization of waste straw and improve fertilizer efficiency, a novel semi-interpenetrating polymer network fertilizer (MSP-g-AA/PVA-APP) synthesized from straw cellulose and linear polymer was prepared by solution polymerization. The ammonium polyphosphate (APP) was introduced to supply nitrogen and phosphorus nutrients. The prepared materials were characterized with scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD) and thermogravimetric analysis (TGA). The water absorbency and slow-release behavior of MSP-g-AA/PVA-APP were also studied. The results indicated that MSP-g-AA/PVA-APP exhibited excellent water absorbency of 681.3 g/g in distilled water and enhanced the water retention capacity of soil. The cumulative N and P release rates of MSP-g-AA/PVA-APP were 55.1 % and 47.3 % after 30 days in soil, respectively. The effect of MSP-g-AA/PVA-APP on growth of wheat was studied, and the results show that the application products could facilitate the growth of wheat. It could be concluded that the product with water retention and slow-release property, being low costs and friendly to environment, had great potential for application in agricultural. [ABSTRACT FROM AUTHOR]

Research on the service values of urban ecosystems is a hot topic of ecological studies in the current era of rapid urbanization. To quantitatively estimate the ecosystem service value in Chengdu, China from the perspectives of natural ecology and social ecology, the technologies of remote sensing (RS) and geographic information system (GIS) are utilized in this study to extract the land use type information from RS images of Chengdu in 2003, 2007, 2013 and 2018. Subsequently, a driver analysis of the ecosystem services of Chengdu was performed based on socioeconomic data from the last 16 years. The results indicated that: (1) from 2003 to 2018, the land utilization in Chengdu changed significantly, with the area of cultivated lands, forest lands and water decreasing remarkably, while the area of construction lands dramatically increased. (2) The ecosystem services value (ESV) of Chengdu decreased by 30.92% in the last 16 years, from CNY 2.4078 × 1010 in 2003 to CNY 1.6632 × 1010 in 2018. Based on a future simulation, the ESV is further predicted to be reduced to CNY 1.4261 × 1010 by 2033. (3) The ESV of Chengdu showed a negative correlation with the total population, the urbanization rate and the per capita GDP of the region, indicating that the ESV of the studied region was inter-coupled with the socioeconomic development and can be maintained at a high level through rationally regulating the socioeconomic structure. [ABSTRACT FROM AUTHOR]

In order to enhance utilization of millet straw and reduce fertilizer loss, a novel multifunctional fertilizer (MS-g-PAA/PDMUA) was developed using straw cellulose and linear polymer (PDMUA) by semi-interpenetrating technology. The structure and morphology characterization of MS-g-PAA/PDMUA were measured by fourier-transform infrared, x-ray diffraction, x-photoelectron spectroscopy and scanning electron microscopy techniques, to provide evidence of semi-IPNs networks and component interactions, and the results show that the product exhibited excellent water absorbency (562.3 g/g) and enhanced the soil infiltration. Cumulative release of N, P was 49.2% and 55.1%, respectively, after 40 days, coming up to the Committee of European Normalization (CEN) standard. The agricultural application of MS-g-PAA/PDMUA showed that it could promote growth indexes of wheat, which could improve wheat yields. Therefore, desirable water retention, slow-release properties, and wheat growth effects highlight the product's potential for agriculture application. [Display omitted] ● MS-g-PAA/PDMUA is derived from millet straw, can enhance waste straw utilization. ● The MS-g-PAA/PDMUA is rich in nitrogen and phosphorus, which promote wheat growth. ● The product has excellent water retention and slow fertilizer-release properties. ● Preparing by waste straw can reduce cost, is beneficial to industrial production. [ABSTRACT FROM AUTHOR]

This study aim to investigate the biodegradation of all alkanes in soil by adding stimulater and indigenous bacteria. The experiments were carried out by adding native bacteria and the stimulater to the soil S1 (total petroleum hydrocarbon (TPH) = 22,745 mg/kg) and soil S2 (TPH = 13,833 mg/kg) to explored the effect and mechanism of the stimulated biodegradation of all alkanes in soil. The results showed that most alkanes were used as the main carbon source of TPH in the late stimulation stage, so that all alkanes could be biodegraded by stimulating. The biodegradation of C 10 - C 19 (4527 mg/kg) and C 20 - C 30 (8530 mg/kg) were much higher than the stimulated biodegradation of partial alkanes, which indicated that the biodegradation effect of TPH was greatly improved. In addition, for the stimulated biodegradation of all alkanes group, the relative activity of TPH (TPH biodegradation/DOC consumption) was nearly 5 times that of the stimulated biodegradation of partial alkanes group in the late stimulation stage. The amount of ammonia allocated to TPH in the late stimulation stage was nearly 10 times that of DOC, and the organic matter components changed greatly in the early stimulation stage, but there was basically no change in the later stage. It showed that the hydrocarbon degraders in the stimulated biodegradation of all alkanes group used DOC as the main carbon source in the early stimulation stage and mainly degrade TPH in the later stage, which improved the biodegradation efficiency of petroleum hydrocarbons. The mechanism for stimulated biodegradation of all alkanes in oil-contaminated soils. [Display omitted] • Stimulated biodegradation of all alkanes degraded crude oil efficiently in soils. • For the later stimulation stage of all alkanes, most ammonia was distributed to TPH. • For the stimulated biodegradation of all alkanes, high ammonia partition coefficients were key factors. • The organic matter changed significantly in the early stimulation stage, but hardly changed in the later stage. [ABSTRACT FROM AUTHOR]

To enhance waste straw utilization and improve fertilizer efficiency, a novel semi-interpenetrating polymer network fertilizer (CMCK-g-PAA/PDMUP) was prepared from straw cellulose and linear polymer by solution polymerization. Polydihydroxymethyl-urea potassium phosphate (PDMUP) was included to supply nitrogen, phosphorus, and potassium nutrients. Characterization of CMCK-g-PAA/PDMUP with FTIR, XPS, XRD, and SEM techniques provided evidence for semi-interpenetrating polymer networks (semi-IPNs) and component interactions. The prepared product exhibited excellent water absorbency (681.3 g/g) and enhanced the soil's water-retention capacity. Cumulative release of N, P, and K was 56.1%, 64.3%, and 74.1%, respectively, after 40 days–meeting a Committee of European Normalization (CEN) standard. Agricultural application of CMCK-g-PAA/PDMUP promoted wheat growth. Desirable water retention, slow-release properties, and wheat growth effects highlight the product's potential for improving agriculture. Unlabelled Image • Application of the polymer (CMCK-g-PAA/PDMUP) could achieve utilization of waste straw. • The CMCK-g-PAA/PDMUP is derived from waste straw and rich in fertilizers (N, P and K). • The product had excellent water retention and slow-release properties. • The product prepared by waste straw can reduces production cost and promote plant growth. [ABSTRACT FROM AUTHOR]

Biochar application is considered an effective method of reducing nitrous oxide (N 2 O) emissions in soil. However, the mechanism and temporal effect of different doses of biochar on N 2 O emissions is still obscure. Here, we conducted a two-year field experiment to test the effects of different input amounts and frequencies of biochar on soil N 2 O emissions in North China. Biochar was applied in six different treatments in a winter wheat and summer maize rotation system: applications of 0 t/ha biochar (C0), 2.25 t/ha biochar (C1), 4.5 t/ha biochar (C2), 9 t/ha biochar (C3), and 13.5 t/ha biochar (C4) each year, and a single application of 13.5 t/ha biochar (CS) in the first year. The results showed that biochar could inhibit N 2 O emissions, reaching 20.6% to 60.1% in the wheat season and 18.1% to 39.4% in the maize season. The inhibitory effect of biochar on soil N 2 O emissions was dependent on amount and time. C3 had the best results in the wheat season, although its inhibitory effect in the maize season was not as good relative to C4 due to the lower biochar application. In addition, CS significantly reduced (27.7%) the cumulative N 2 O emissions in the first year, although the inhibitory effect disappeared in the second year. Biochar increased the nosZ gene copy numbers and promoted a reduction of N 2 O in the soil via the denitrification process. In conclusion, the inhibition of N 2 O emissions during denitrification is an important factor for reducing soil N 2 O emissions by biochar, and the inhibition of biochar is influenced by the input amount and time. Unlabelled Image • Biochar could reduce soil N 2 O emissions through regulating denitrification. • The inhibit effect of biochar on N 2 O emissions decreased with the time. • The nosZ gene and the soil NO 3 −-N were the main factors affecting N 2 O emissions. [ABSTRACT FROM AUTHOR]

A high rate of elemental sulfur (S 0 ) accumulation from sulfide-containing wastewater has great significance in terms of resource recovery and pollution control. This experimental study used Thiobacillus denitrificans and denitrifying bacteria incorporated with signal molecules (C6 and OHHL) for simultaneous sulfide (S 2- ) and nitrate (NO 3 - ) removal in synthetic wastewater. Also, the effects on S 0 accumulation due to changes in organic matter composition and bacteria proportion through signal molecules were analyzed. The 99.0% of S 2- removal and 99.3% of NO 3 - was achieved with 66% of S 0 accumulation under the active S 2- removal group. The S 0 accumulation, S 2- and NO 3 - removal mainly occurred in 0-48 h. The S 0 accumulation in the active S 2- removal group was 2.0-6.3 times higher than the inactive S 2- removal groups. In addition, S 0 /SO 4 2- ratio exhibited that S 0 conversion almost linearly increased with reaction time under the active S 2- removal group. The proportion of Thiobacillus denitrificans and H + consumption showed a positive correlation with S 0 accumulation. However, a very high or low ratio of H + /S 0 is not suitable for S 0 accumulation. The signal molecules greatly increased the concentration of protein-I and protein-II, which resulted in the high proportion of Thiobacillus denitrificans . Therefore, high S 0 accumulation was achieved as Thiobacillus denitrificans regulated the H + consumption and electron transfer rate and provided suppressed oxygen environment. This technology is cost-effective and commercially applicable for recovering S 0 from wastewater.

Polydisperse water-soluble gold nanoclusters (AuNCs) protected by penicillamine have been synthesized in this work. The sequential size-selective precipitation (SSSP) technique has been applied for the size fractionation and purification of the monolayer-protected AuNCs. Through continuously adding acetone to a crude AuNC aqueous solution and controlling the volume percentage of acetone, we successfully separated the polydisperse AuNCs with diameters ranging from 0.5 to 5.4 nm into four different fractions sequentially. High-resolution transmission electron microscopy (HRTEM) shows that the four fractions are well-dispersed spherical particles of diameter 3.0 ± 0.6, 2.3 ± 0.5, 1.7 ± 0.4, and 1.2 ± 0.4 nm. Proton nuclear magnetic resonance spectroscopy suggests that disulfide, excess ligands and gold(I) complexes were removed from the AuNCs fractions. These results demonstrate the considerable potential of the SSSP technique for size-based separation and purification of AuNCs, achieving not only the isolation of larger nanoclusters (NCs) from small NCs in a continuous fashion, but also for the removal of small-molecule impurities. Based on the results from the mass spectrometry and thermogravimetric analysis, the average composition of the four fractions can be represented by Au 38 (SR) 18 , Au 28 (SR) 15 , Au 18 (SR) 12 , and Au 11 (SR) 8 , respectively. This indicates that the SSSP separation is mainly dependent on the core size and the ratio of Au atoms to ligands of AuNCs. X-ray photoelectron spectroscopy (XPS) has also been applied to observe the molecular dependence on the gold and sulfur chemical state of organosulfur monolayers of the fractions. The photoluminescence spectra of these AuNCs in the range of 900-790 nm was investigated at room temperature. The results show that the peak emission energy of the size-selected AuNCs undergoes a blue shift when the size is decreased, which can be attributed to the quantum confinement effect.