Search

Poly(ethylene glycol) (PEG) is well known to endow nanoparticles (NPs) with low-fouling and stealth-like properties that can reduce immune system clearance in vivo, making PEG-based NPs (particularly sub-100 nm) of interest for diverse biomedical applications. However, the preparation of sub-100 nm PEG NPs with controllable size and morphology is challenging. Herein, we report a strategy based on the noncovalent coordination between PEG-polyphenolic ligands (PEG-gallol) and transition metal ions using a water-in-oil microemulsion phase to synthesize sub-100 nm PEG NPs with tunable size and morphology. The metal-phenolic coordination drives the self-assembly of the PEG-gallol/metal NPs: complexation between MnII and PEG-gallol within the microemulsions yields a series of metal-stabilized PEG NPs, including 30-50 nm solid and hollow NPs, depending on the MnII/gallol feed ratio. Variations in size and morphology are attributed to the changes in hydrophobicity of the PEG-gallol/MnII complexes at varying MnII/gallol ratios based on contact angle measurements. Small-angle X-ray scattering analysis, which is used to monitor the particle size and intermolecular interactions during NP evolution, reveals that ionic interactions are the dominant driving force in the formation of the PEG-gallol/MnII NPs. pH and cytotoxicity studies, and the low-fouling properties of the PEG-gallol/MnII NPs confirm their high biocompatibility and functionality, suggesting that PEG polyphenol-metal NPs are promising systems for biomedical applications.

The substitution of petroleum-based self-healing elastomers with biobased counterparts is crucial to the global sustainable development of the rubber industry, which highly depends on the ease of t...

With increasing urban area and population, global cities are playing a more important role in the alteration of the global biogeochemical cycles. The aims of this study are to understand the concentrations and stoichiometric relations of biogenic elements (C, N, and P) in urban soils, further to reveal the effects of C, N, and P accumulation on the urban environment. We collected 317 surface (0–10 cm) soil samples taken from Nanjing, China, a typical city with more than 2000 years of history. These soil samples were located in different urban zones of Nanjing with different land use histories. The soil C, N, and P concentrations were determined. The stoichiometric relations of soil C, N, and P were investigated in urban soils. Meanwhile, some studies on sources of C, N, and P in diverse urban settings from literature were combined to explore the universal rule of C, N, and P cycling and their ecological and environmental effects in urban area. Compared to rural soils, more C, N, and P are accumulated in the urban soils, which also change their stoichiometric relations. The concentrations of OC, TN, and TP in urban top soils are 17.0 ± 9.69 g kg−1, 1.53 ± 0.92 g kg−1, and 1.31 ± 0.67 g kg−1, respectively. The mean atomic ratio of C:N:P is 37:3:1 in the surface of urban soils that strictly differs from natural soils in China and the whole world. The mean of C:N ratio in urban soils is similar to that of agriculture, grassland, and forest soils. However, the ratios of C:P and N:P in urban soils are much lower than that in agricultural, forest, and grassland soils. This implies that P is extremely enriched in the urban soils. The high C in urban soils are considered coming from natural and anthropogenic sources. The high N and P mainly come from anthropogenic sources. The well-constrained C:N:P ratio in rural soils does not apply for urban soils. The abnormal C:N:P ratio of urban soils is the result of unbalanced accumulation of C, N, and P from human activities. Urban soils are already an important storage of carbon. High N and P in urban soils may bring threat of surface water eutrophication and ground water contamination. These effects are expected to increase with the city development time.

We report a facile strategy for engineering diverse particles based on the supramolecular assembly of natural polyphenols and a self-polymerizable aromatic dithiol. In aqueous conditions, uniform and size-tunable supramolecular particles are assembled through π–π interactions as mediated by polyphenols. Owing to the high binding affinity of phenolic motifs present at the surface, these particles allow for the subsequent deposition of various materials (i.e., organic, inorganic, and hybrid components), producing a variety of monodisperse functional particles. Moreover, the solvent-dependent disassembly of the supramolecular networks enables their removal, generating a wide range of corresponding hollow structures including capsules and yolk–shell structures. The versatility of these supramolecular networks, combined with their negligible cytotoxicity provides a pathway for the rational design of a range of particle systems (including core–shell, hollow, and yolk–shell) with potential in biomedical and environmental applications., Monodisperse colloidal particles with tunable properties show promise for biomedical, energy, and environmental applications and simple routes for fabricating these particles are of interest. Here, the authors report a facile strategy for fabrication of diverse particles based on the supramolecular assembly of phenols and self-polymerizable thiols

Insect neuropeptides play an important role in regulating physiological functions such as growth, development, behavior and reproduction. We identified temperature‐sensitive neuropeptides and receptor genes of the cotton whitefly, Bemisia tabaci. We identified 38 neuropeptide precursor genes and 35 neuropeptide receptors and constructed a phylogenetic tree using additional data from other insects. As temperature adaptability enables B. tabaci to colonize a diversity of habitats, we performed quantitative polymerase chain reaction with two temperature stresses (low = 4 °C and high = 40 °C) to screen for temperature‐sensitive neuropeptides. We found many neuropeptides and receptors that may be involved in the temperature adaptability of B. tabaci. This study is the first to identify B. tabaci neuropeptides and their receptors, and it will help to reveal the roles of neuropeptides in temperature adaptation of B. tabaci.

Sensor scheduling is used to improve the sensing performance in the estimation of targets' states. However, few papers are on the sensor scheduling for target detection with guiding information. This letter can remedy this deficiency. A risk-based target detection method with guiding information is provided firstly, based on which, the sensor scheduling approach is aiming at reducing the risk and uncertainty in target detection, namely risk-based sensor scheduling method. What should be stressed is that the Prediction Formula in sensor scheduling is proposed. Lastly, some examples are conducted to stress the effectiveness of this proposed method.

In decades, the battlefield environment is becoming more and more complex with plenty of electronic equipments. Thus, in order to improve the survivability of radar sensors and satisfy the requirement of maneuvering target tracking with a low probability of intercept, a non-myopic scheduling is proposed to minimize the radiation cost with tracking accuracy constraint. At first, the scheduling problem is formulated as a partially observable Markov decision process (POMDP). Then the tracking accuracy and radiation cost over the future finite time horizon are predicted by the posterior carmer-rao lower bound (PCRLB) and the hidden Markov model filter, respectively. Finally, the proposed scheduling is implemented efficiently by utilizing the branch and bound (B&B) pruning algorithm. Simulation results show that the performance of maneuvering target tracking was improved by the improved interacting multiple model (IMM), and the scheduler time and maximum memory consumption were significant reduced by the present B&B pruning algorithm without losing the optimal solution.

Asparagus stem blight caused by Phomopsis asparagi is a major hindrance to asparagus production worldwide. Currently, fungicides are used to manage the disease in commercial production, but resistance to common fungicides has emerged in the wild population. In the present study, 132 isolates of P. asparagi collected from different provinces in China were tested for sensitivities to pyraclostrobin, tebuconazole, and fluazinam. We also determined the efficacies of six fungicides against P. asparagi. The frequency distributions of EC50 values of the isolates tested were unimodal, but the curves for pyraclostrobin and tebuconazole had long right-hand tails. The mean EC50 values for pyraclostrobin, tebuconazole, and fluazinam were 0.0426 ± 0.0029, 0.6041 ± 0.0416, and 0.0314 ± 0.0013 μg/ml, respectively. In addition, the EC50 values for pyraclostrobin were very similar with or without salicylhydroxamic acid (SHAM), 20 μg/ml, indicating that SHAM is not needed to determine the sensitivity of P. asparagi to pyraclostrobin when using the mycelial growth inhibition assay. In greenhouse assays, Merivon (42.4% fluxapyroxad plus pyraclostrobin SC), Frown-cide (500 g/liter fluazinam SC), Cabrio (250 g/liter pyraclostrobin EC), and Nativo (75% trifloxystrobin plus tebuconazole WG) showed excellent preventive efficacy against P. asparagi. And these fungicides were more effective before inoculation than when they were applied after inoculation (P < 0.05). Therefore, these fungicides should be applied prior to infection to control stem blight. In field trials, Frown-cide, Merivon, Nativo, and Cabrio also performed good control effects, ranging from 75.2 to 86.0% in 2017 and 75.4 to 87.1% in 2018. We demonstrated that Frown-cide, Merivon, Nativo, and Cabrio had considerable potential to manage asparagus stem blight. In addition, rotations of these fungicides are essential for precluding or delaying the development of resistance and for controlling the disease.

Purple paddy soils cover about 66% of the paddy soils in Sichuan Basin. Complex interactions made the effects of potassium fertilizer application on NH4+ adsorption more complicated and the behavior of NH4+ and K+ interaction in purple paddy soils has rarely been evaluated. We hypothesize that correct management of these soils can enhance the efficiency of ammonium and potassium fertilizers. In order to determine correct management methods, it is important to understand the interaction of main nutrient cations NH4+ and K+ and maturation hydroponics in purple paddy soils with different paddy cultivation times. A purple paddy soil chronosequence with cultivation history from 0 to 300 years was studied to understand the respective effects of SOM and mineralogy on NH4+ and K+ sorption behavior by adsorption experiments using samples both before and after H2O2 oxidation. The study shows that maturation hydroponics influenced NH4+ and K+ adsorption mainly through changing clay mineralogy and enhancing SOM accumulation. SOM and smectite play positive effects for NH4+ adsorption. The K+ adsorption, however, is mainly affected by the smectite changes. The adsorption percentages are obviously higher at 25–50 mg L−1 for each NH4+ solution and higher at 50–100 mg L−1 for each K+ solution. When ammonium and potassium were applied together, NH4+ and K+ adsorption are mutually weakened. In addition, the percentage of K+ adsorption increased from 49.7–57.7% for the 100 mg L−1 K+ solution to 50.9–58.5% for the 200 mg L−1 K+ solution at 200 mg L−1 of added NH4+. SOM enrichments could be a positive way to improve the ammonium fertilizer utilization efficiency in purple paddy soils. Potassium may be more vulnerable to loss at low K+ concentrations given that ammonium and potassium fertilizers were applied together and it should be separately applied to enhance the utilization efficiency of applied fertilizer.

Endo/lysosomal escape and gene release are two critical bottlenecks in gene delivery. Herein, a novel photo-controllable metal-organic frameworks (MOFs) nanoswitch is rationally designed for enhancing small interfering RNA (siRNA) delivery. One single laser triggers the “off-to-on” switching of MOFs nanocomplexes, inducing significant siRNA release accompanied by rapid MOFs dissociation into protonatable 2-methylimidazalo and osmotic rupturing Zn2+ ions, which cooperatively contribute to remarkable endo/lysosomal rupture (∼ 90%). The simultaneous endo/lysosomal rupture and release enable a high spatio-temporal control on RNA interference for effective cancer therapy. Notably, the “off-to-on” switching also activates fluorescence recovery for real-time monitoring siRNA delivery. The nanoswitch could easily be extended to deliver other therapeutic agents (e.g., DNA, protein, anticancer drug) for overcoming endo/lysosomal entrapment.

Depth patterns of soil microbial distribution have not been well characterized and little is known about the balance between stochastic and deterministic processes in shaping microbial community th...

To probe Fe isotopic signatures of the Quaternary Red Clay (QRC) in subtropical southeastern China, two QRC profiles located in southern Anhui Province, Southeast China, were studied. The whole profiles were generally in a narrow range in δ 56 Fe of −0.040 ± 0.061‰—0.117 ± 0.048‰. The Yellow-brown Earth (YBE) and Uniform Red Clay (URC) of the upper profiles were similar in δ 56 Fe to the Xiashu Loess along the Yangtze River, Southeast China, and the loess, paleosols and Tertiary red clay in the Chinese Loess Plateaus, Northwest China, as well as the baseline of terrestrial igneous rocks. The slight variation of δ 56 Fe from the YBE to the URC suggests that the chemical weathering and rubification on the aerobic surface did not fractionate Fe isotopes significantly. The Reticulate Red Clay (RRC) underlying the YBE and URC fluctuated in δ 56 Fe to some extent. The white veins separated from the lower RRC were depleted of Fe oxides and heavier in Fe isotopes, and the red veins, on the contrary, were isotopically lighter in Fe. δ 56 Fe of the white veins, 0.345 ± 0.053‰ on average, was significantly higher than the bulk samples, 0.033 ± 0.044‰ on average, and the red veins, −0.021 ± 0.046‰ on average. This suggests that the reticulate textures of the RRC were formed by the reductive removal/re-precipitation of Fe due to the cyclical changes of redoxic conditions. Fe isotopic composition of the QRC was dominantly controlled by the redoxic mobility of Fe, rather than the degree of weathering. δ 56 Fe of the profiles was not correlated with the paleoclimatic events, and thus cannot be used as a paleoclimatic proxy. The fractionation of Fe isotopes in the lower RRC, however, indicated the occurrence of over-humid paleoclimate with alternations between drought and wetness in Southern China during the Pleistocene.

Background Water stress is one of the serious abiotic stresses that negatively influences the growth, development and production of sugarcane in arid and semi-arid regions. However, silicon (Si) has been applied as an alleviation strategy subjected to environmental stresses. Methods In this experiment, Si was applied as soil irrigation in sugarcane plants to understand the mitigation effect of Si against harmful impact of water stress on photosynthetic leaf gas exchange. Results In the present study we primarily revealed the consequences of low soil moisture content, which affect overall plant performance of sugarcane significantly. Silicon application reduced the adverse effects of water stress by improving the net photosynthetic assimilation rate (Anet) 1.35–18.75%, stomatal conductance to water vapour (gs) 3.26–21.57% and rate of transpiration (E) 1.16–17.83%. The mathematical models developed from the proposed hypothesis explained the functional relationships between photosynthetic responses of Si application and water stress mitigation. Conclusions Silicon application showed high ameliorative effects on photosynthetic responses of sugarcane to water stress and could be used for mitigating environmental stresses in other crops, too, in future.

Spatial prediction is an important approach to obtain location-specific values of soil electrical conductivity (EC), which is a proxy of soil salinity and important for agricultural management in arid and semi-arid areas. Linear regression models assume that the relation between soil EC and environmental covariates is constant over the area to be predicted. This is problematic at the regional scale, at which some of the regression parameters may indeed be globally constant, whereas others may vary locally. Moreover, model residuals often exhibit spatial dependence, which invalidates the ordinary least squares linear regression. This study examined the combination of a mixed geographically weighted regression model with simple kriging of the residuals (MGWGK) for mapping soil EC in the Heihe River Basin, an inland river basin in arid northwest China. We compared the performance of MGWRK with those of multiple linear regression (MLR), regression kriging (RK), geographically weighted regression (GWR), geographically weighted regression kriging (GWRK) and mixed geographically weighted regression (MGWR). Environmental covariates were developed from spatial information on topography, climate, vegetation, and geographic position. A ten-fold cross-validation was applied to evaluate predictive accuracy of the various methods. Soil EC ranged from 0.031 to 182.100 dS m−1, exhibiting a contrasting distribution of soil EC in the upper, middle, and lower river reaches. The MGWRK method outperformed other methods. The effects of different environmental covariates on soil EC were revealed by the fixed and geographically varying parameters of MGWRK. The nugget-to-sill ratios of fitted variogram models all fell between 25 and 32%, exhibiting moderate spatial autocorrelation of models residuals. Predictive accuracy was improved by MGWRK, as the spatial dependence of model residuals were included in the prediction. When selecting an optimal linear regression model, covariates should be tested to see if they are constant (as in MLR) or spatially varying (as in GWR) or semi-varying (as in MGWR), and model residuals should be tested for spatial dependence (as in MGWRK).

The development of multiple drug resistance (MDR) to chemotherapy and subsequent treatment failures are major obstacles in cancer therapy. An attractive option for combating MDR is inhibiting the expression of P-glycoprotein (P-gp) in tumor cells. Here, we report a novel chemosensitizing agent, XMD8-92, which can down-regulate P-gp. To enhance the specificity of MDR chemotherapy, a promising nanotheranostic micelle system based on poly(ethylene glycol)-blocked-poly(L-leucine) (PEG-b-Leu) was developed to simultaneously carry the anticancer drug doxorubicin, chemosensitizing agent XMD8-92, and superparamagnetic iron oxide nanoparticles (SPIOs). Featured with MDR environmentally responsive dual-targeting capability, controllable drug delivery, and efficient magnetic resonance (MR) imaging characteristics, the prepared nanotheranostics (DXS@NPs) showed outstanding in vitro cytotoxicity on MDR cells (SCG 7901/VCR) with only 53% of cells surviving compared to 90% of DOX-treated cells. Furthermore, efficient tumor inhibition and highly reduced systemic toxicity were exhibited by MDR tumor-bearing mice treated with DXS@NPs. Overall, the environmentally responsive dual-targeting nanotheranostics represent a promising approach for overcoming cancer MDR.

Organic carbon (OC) plays a pivotal role in earth surface systems. However, current three-dimensional (3D) mapping studies usually focus on a soil depth of 1 m rather than the depth to the bedrock. A top-down method using piecewise depth functions was proposed to fit the OC vertical decline patterns in a subtropical catchment in southern China. The vertical variation in OC was greatly affected by the heterogeneous topsoil due to natural processes and anthropogenic disturbances. Thus, topsoil OC maps were produced and utilized as covariates to indicate the OC decline rates and to benefit the 3D OC simulation. A distribution map of the underground critical zone thickness (UCZT) was applied as a lower boundary for the 3D simulation. Six widely used mapping techniques were performed to predict the spatial distribution of topsoil OC and depth function parameters. The overall cross-validation results showed a root mean squared error (RMSE) of 1.7 g kg–¹ and a ratio of performance to deviation (RPD) of 1.82. Given limited boreholes, validation showed that the depth function performed better in the lower part (>1 m) than in the upper part (

Selective self-assembly in multicomponent mixtures offers a method for isolating desired components from complex systems for the rapid production of functional materials. Developing approaches capable of selective assembly of "target" components into intended three-dimensional structures is challenging because of the intrinsically high complexity of multicomponent systems. Herein, we report the selective coordination-driven self-assembly of metal-phenolic networks (MPNs) from a series of complex multicomponent systems (including crude plant extracts) into thin films via metal chelation with phenolic ligands. The metal (FeIII) selectively assembles low abundant phenolic components (e.g., myricetrin and quercetrin) from plant extracts into thin films. This selective metal-phenolic assembly is independent of the substrate properties (e.g., size, surface charge, and shape). Moreover, the high selectivity is consistent across different target phenolic ligands in model mixtures, even though each individual component can form thin films from single-component systems. A computational simulation of film formation suggests that the driving force for the selective behavior stems from differences in the number of chelating sites in the phenolic structures. The MPN films are shown to demonstrate improved antioxidant properties compared with the corresponding phenolic compounds in their free form, therefore exhibiting potential as free-standing antioxidant films.

Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.

Nitrate accumulation has been reported in the top 1 m and subsurface soil (> 1 m) across arid to semi-humid regions, but not in humid regions. Nitrate inventories through the whole regolith, referred to collectively as soil and saprolite, in humid regions have received little attention to date, likely due to previously assumed low nitrification rates and large nitrogen (N) losses by severe surface runoff and erosion. In order to understand if and how reactive N exists in the below ground (soil and saprolite) in humid environment, the amount of NO3--N, NH4+-N and dissolved organic N (DON) present in the regolith to a depth of 9 m in a typical red soil Critical Zone was investigated under different land uses (upland, woodland and paddy field). The Red Soil Critical Zone Observatory is located in the subtropical Jiangxi Province, China, with a mean annual precipitation of 1795 mm and mean annual potential evapotranspiration of 1229 mm. The examined regoliths were acidic, highly weathered, and mainly clay loam in texture. Results showed that on average 92% (827 ± 97 kg N ha-1) of NO3--N and 82% (521 ± 153 kg N ha-1) of DON were stored at depth (from a depth of 1 m to the bedrock surface) in the upland regolith, while 92% (283 kg N ha-1) of NO3--N and 78% (820 kg N ha-1) of DON were stored at depth in the woodland regolith. Nitrate N significantly accumulated with depth in the upland regolith from the 1- to 4-m depth interval (p < 0.01), while the inventory (632 ± 75 kg N ha-1) in the top 3-m zone accounted for on average 71% of the total. Dissolved organic N significantly accumulated with depth in the upland regolith from the 0- to 3-m depth interval (p < 0.01), while the inventory (408 ± 75 kg N ha-1) in the top 3-m zone accounted for on average 64% of the total. There was no significant accumulation for NH4+-N throughout the upland regolith (p = 0.35). No substantial accumulation of dissolved N was measured at depth in paddy field regoliths with different cultivation ages. The finding that large reservoirs of reactive N can exist in deep regolith rather than in the routinely investigated solum of subtropical regions shows a missing part of the terrestrial N budget and raises concerns about potential 34 groundwater nitrate pollution.

The soil's pH is the single most important indicator of the soil's quality, whether for agriculture, pollution control or environmental health and ecosystem functioning. Well documented data on soil pH are sparse for the whole of China — data for only 4700 soil profiles were available from China's Second National Soil Inventory. By combining those data, standardized for the topsoil (0–20 cm), with 17 environmental covariates at a fine resolution (3 arc-second or 90 m) we have predicted the soil's pH at that resolution, that is at more than 109 points. We did so by parallel computing over tiles, each 100 km × 100 km, with two machine learning techniques, namely Random Forest and XGBoost. The predictions for the tiles were then merged into a single map of soil pH for the whole of China. The quality of the predictions were assessed by cross-validation. The root mean squared error (RMSE) was an acceptable 0.71 pH units per point, and Lin's Concordance Correlation Coefficient was 0.84. The hybrid model revealed that climate (mean annual precipitation and mean annual temperature) and soil type were the main factors determining the soil's pH. The pH map showed acid soil mainly in southern and north-eastern China, and alkaline soil dominant in northern and western China. This map can provide a benchmark against which to evaluate the impacts of changes in land use and climate on the soil's pH, and it can guide advisors and agencies who make decisions on remediation and prevention of soil acidification, salinization and pollution by heavy metals, for which we provide examples for cadmium and mercury.

Chinese pearl barley (Coix chinensis Tod.) is grown worldwide as a cereal food and medicinal plant. During 2016 and 2017, a severe leaf blight outbreak was observed in Nanjing prefecture, Fujian Pr...

Modern monothetic hierarchical soil classification systems such as the Chinese Soil Taxonomy (CST) are semi‐quantitative and their future development is likely to trend towards a fully quantitative system using the concepts of numerical taxonomy. Previous researchers have calculated the taxonomic distances between individual soils based on soil physiochemical properties, not, however, based on spectra of full soil profiles with different horizons. We hypothesized that numerical taxonomy implemented by cluster analysis of the taxonomic distance matrix based on vis–NIR spectra would accord with some CST Orders assigned by pedologists, and not with others, depending on how closely spectral features represent the diagnostic features used in the classification. Taxonomic distances in spectral space were computed for all pairs of 191 profiles, resulting in a distance matrix on which hierarchical cluster analysis was performed. Different indices were calculated to determine the optimum number of clusters, resulting in four spectral soil classes. These were then compared with CST Orders assigned to the profiles by expert allocation. The numerical classes and CST Orders matched poorly because of the completely different classification philosophies behind numerical taxonomy and the CST, which is based largely on presumed genesis and uses sharp thresholds leading to very similar soils being allocated to different classes. Thus, we consider the numerical classification as information that is complementary to the monothetic hierarchical system. Numerical classification can reveal the taxonomic objective aspects of the relation between the defined classes and can suggest new groupings. HIGHLIGHTS: Taxonomic distances can serve as an objective measure of soil similarity. Soil spectra are a good candidate for numerical classification based on taxonomic distances. The conceptual basis of Chinese Soil Taxonomy (CST) does not match that of taxonomic distance. Numerical classification based on spectra can suggest revisions to the CST.

The concentration of soil organic carbon (SOC) is one of the most important soil properties, and its spatio-temporal variability greatly affects the global climate and agroecology. To investigate the effects of land use and climate change on SOC, a heuristic cellular automaton (HCA) model was proposed and applied to a plains area in eastern China with a high population density and rapid urbanization rate. The HCA model was designed to simulate the geographical variation in SOC dynamics over the long term (2080), and lateral carbon (C) migration is represented by revised neighbourhood variables at the macro scale. Three widely used soil mapping techniques were applied for comparison: multiple linear regression (MLR), support vector machine (SVM) and kriging with external drift (KED). The HCA model enhanced the accuracy of the predicted SOC by 15.27% over MLR, 12.31% over SVM and 10.98% over KED. Future land use maps were produced using legacy land use data and artificial neural network-based cellular automata (CA), and the simulation results showed the rapid urbanization of this area, where the percentage of cropland declined by 23.75% and that of village/urban areas increased by 22.90% from 2010 to 2080. The overall SOC concentrations are anticipated to increase by 2080 given the rising mean annual air temperature and mean annual precipitation. Our results also suggested that land use change clearly influenced the change in soil C, with village/urban areas exhibiting higher SOC than cropland. To provide stakeholders with accurate soil information, it is important to understand the comprehensive impacts of land use and climate change on soil evolution; this study illustrates the value of integrating pedogenetic information in soil C simulation models.

The soil organic carbon (SOC) and total nitrogen (TN) of topsoil could be greatly affected by the conversion of grassland to cropland (CGC) due to vegetation harvesting and soil erosion. However, few studies have evaluated the effects of these changes in the subsoil and distinguished its main controls at the regional scale. This paper investigated the total changes in the SOC stock (SOCS) and TN stock (TNS) of soils from 0 to 30 cm and 0–100 cm in depth over the past three decades in the Songnen Plain, China, a typical Mollisol region. The CGC resulted in a moderate loss of topsoil C and N but an increase in subsoil C and N, and the soil mapping results showed that approximately 7.47 × 1011 kg C and 1.51 × 1011 kg N were accumulated during the past three decades. Prediction uncertainty was assessed by 100 model runs with random jackknife partitions, and high uncertainty was found in the areas with rapidly changing SOCS and TNS levels. Our findings indicated that subsoil should be considered in the estimation of the SOCS and TNS at the regional scale. The SOCS and TNS of the CGC areas were anticipated to increase after long-term cultivation. In view of ongoing cropland expansion, up-to-date land use and soil type data are vital for selecting monitoring sites and understanding long-term soil evolution at the regional scale.

Soil diagnostic horizons, which each have a set of quantified properties, play a key role in soil classification. However, they are difficult to predict, and few attempts have been made to map their spatial occurrence. We evaluated and compared four machine learning algorithms, namely, the classification and regression tree (CART), random forest (RF), boosted regression trees (BRT), and support vector machine (SVM), to map the occurrence of the soil mattic horizon in the northeastern Qinghai-Tibetan Plateau using readily available ancillary data. The mechanisms of resampling and ensemble techniques significantly improved prediction accuracies (measured based on area under the receiver operator characteristic curve score (AUC)) and produced more stable results for the BRT (AUC of 0.921 ± 0.012, mean ± standard deviation) and RF (0.908 ± 0.013) algorithms compared to the CART algorithm (0.784 ± 0.012), which is the most commonly used machine learning method. Although the SVM algorithm yielded a comparable AUC value (0.906 ± 0.006) to the RF and BRT algorithms, it is sensitive to parameter settings, which are extremely time-consuming. Therefore, we consider it inadequate for occurrence-distribution modeling. Considering the obvious advantages of high prediction accuracy, robustness to parameter settings, the ability to estimate uncertainty in prediction, and easy interpretation of predictor variables, BRT seems to be the most desirable method. These results provide an insight into the use of machine learning algorithms to map the mattic horizon and potentially other soil diagnostic horizons.

Visible‐near infrared (vis–NIR) spectroscopy can reveal various soil properties and facilitate soil classification. However, few studies have attempted to classify vertical soil profiles that contain several genetic horizons. Here, we propose the ‘multiple objectives mixed support vector classification’ (MOM–SVC) method to classify soil profiles. A total of 130 soil profiles were collected from genetic horizons in Zhejiang Province, China. After laboratory analysis, soil profiles were classified according to the Chinese Soil Taxonomy system. Vis–NIR spectra were recorded from each genetic horizon of each soil profile and were then pre‐processed. We performed the MOM–SVC method as follows: (i) created a support vector machine (SVM) model (one‐versus‐one approach) using spectral data from all soil horizons in calibration profiles, (ii) applied the SVM model on each horizon of the profile to be predicted, (iii) extracted ‘votes’ from each horizon and mixed (or summarized) them into the votes of each profile to be predicted and (iv) classified each profile by the majority‐voting method. We also investigated whether the additional input of auxiliary soil information (e.g. moist soil colour, soil organic matter and soil texture), which could be measured easily or be well predicted by vis–NIR spectroscopy, could improve the accuracy of soil classification when combined with it. Independent validation results showed that the MOM–SVC method performed better at the soil order level than at the suborder level. Adding auxiliary soil information to the classification model improved the overall accuracy of classification at the soil order level. The proposed MOM–SVC method provides a fast objective diagnostic of soil classes for use in soil surveys and can help to update soil databases when a more objective soil classification system is developed. HIGHLIGHTS: The MOM–SVC method can be used to classify soil profiles objectively with a variety of soil horizons. Stratified random sampling was used to quantify prediction uncertainty in classification MOM–SVC can predict soil orders with greater accuracy than suborders. Adding auxiliary soil information into the classification model improved prediction accuracy.

Plant cell and water relationship regulates morphological, physiological and biochemical characteristics to optimize carboxylation for enhanced biomass yield in sugarcane. Insufficient water irrigation is one of the serious problems to impair potential yield of agriculturally important sugarcane cash crop by loss in plant performance. Our study aims to reveal consequences of foliar spray of silicon (Si) using calcium metasilicate powder (Wollastonite, CaO.SiO2) to alleviate the adverse effects of limited water irrigation in sugarcane. Silicon (0, 50, 100 and 500 ppm) was applied as foliar spray on normally grown 45 days old sugarcane plants. Further, these plants were raised at half field capacity (50%) using water irrigation precisely up to 90 days under open environmental variables. Consequently, restricted irrigation impaired plant growth-development, leaf relative water content (%), photosynthetic pigments, SPAD unit, photosynthetic performance, chlorophyll fluorescence variable yield (Fv/Fm) and biomass yield. Notably, it has enhanced values of proline, hydrogen peroxide (H2O2), malondialdehyde (MDA), antioxidative defense enzyme molecules viz., catalase (CAT), ascorbate peroxidase (APx) and superoxide dismutase (SOD). The foliar spray of Si defended sugarcane plants from limited water irrigation stress as Si quenched harmful effect of water-deficit and also enhanced the operation of antioxidant defense machinery for improved sugarcane plant performance suitably favored stomatal dynamics for photosynthesis and plant productivity.

Nitrate accumulated deep (>100 cm) in the regolith (soil and saprolite) threatens groundwater quality, but most studies focus only on nitrate nearer the surface (

In the dynamic era of climate change, agricultural farming systems are facing various unprecedented problems worldwide. Drought stress is one of the serious abiotic stresses that hinder the growth potential and crop productivity. Silicon (Si) can improve crop yield by enhancing the efficiency of inputs and reducing relevant losses. As a quasi-essential element and the 2nd most abundant element in the Earth’s crust, Si is utilized by plants and applied exogenously to combat drought stress and improve plant performance by increasing physiological, cellular and molecular responses. However, the physiological mechanisms that respond to water stress are still not well defined in Saccharum officinarum plants. To the best of our knowledge, the dynamics of photosynthesis responsive to different exogenous Si levels in Saccharum officinarum has not been reported to date. The current experiment was carried out to assess the protective role of Si in plant growth and photosynthetic responses in Saccharum officinarum under water stress conditions. Saccharum officinarum cv. ‘GT 42’ plants were subjected to drought stress conditions (80–75%, 55–50% and 35–30% of soil moisture) after ten weeks of normal growth, followed by the soil irrigation of Si (0, 100, 300 and 500 mg L−1) for 8 weeks. The results indicated that Si addition mitigated the inhibition in Saccharum officinarum growth and photosynthesis, and improved biomass accumulation during water stress. The photosynthetic responses (photosynthesis, transpiration and stomatal conductance) were found down-regulated under water stress, and it was significantly enhanced by Si application. No phytotoxic effects were monitored even at excess (500 mg L−1). Soil irrigation of 300 mg L−1 of Si was more effective as 100 and 500 mg L−1 under water stress condition. It is concluded that the stress in Saccharum officinarum plants applied with Si was alleviated by improving plant fitness, photosynthetic capacity and biomass accumulation as compared with the control. Thus, this study offers new information towards the assessment of growth, biomass accumulation and physiological changes related to water stress with Si application in plants.

Loess, as an allochthonous material, plays a significant role in the formation of Pleistocene periglacial slope deposits (PPSD), and thus also for Holocene soil formation, in the central European low mountain range. Although the differing loess proportions in different layers of the PPSD have been well recognized, quantitative distribution and mixing processes of loess in PPSD are still not fully understood. Detailed particle-size distribution was applied for quantifying loess proportions in PPSD in a sandstone area in central Germany. The bimodal pattern of the particle-size distribution curves clearly reflected loess and sandstone-weathering material as two components of the loess-affected layers, which allowed for the quantification of these two components by applying a two-endmembers unmixing model. By inspecting variations of particle-size distribution curves both vertically and spatially, we gained insights into the mixing processes of loess in PPSD and Holocene colluvium. Our results suggest that the loess component in upper layers most likely results from the incorporation of preexisting loess. Holocene colluvium and upper layers were thoroughly homogenized by various earth-surface processes. Radiocarbon dating of charcoal indicated strong human impact during historic times. Close correlation between the overall thickness of loess-containing layers and the depth-weighted loess content pointed to the erosional-depositional history at each site. Our research demonstrates the utility of detailed particle-size data for detecting and interpreting geomorphological processes and landscape evolution. It shows that the spatial distribution patterns of loess are subjected not only to topographic factors controlling primary loess deposition, but also to erosional-depositional histories and anthropogenic impact.

A rapid and sensitive stability indicating HPLC method has been developed and validated for the determination of buprenorphine (BPN) in transdermal patch. Chromatographic separation was achieved isocratically on an XBridge(superscript TM) Shield RP18 column with a mobile phase of acetonitrile/0.063 M ammonium bicarbonate buffer (pH 9.5) (58:42, v/v) at the flow rate of 1.5 mL/min with UV absorbance monitoring at 230 nm. The system performance was evaluated and the result showed that BPN and degradation products were separated. Buprenorphine was subjected to neutral, acidic and basic hydrolysis as well as chemical oxidation to evaluate the specificity. The calibration curve of buprenorphine was linear in the range of 30~70 μg/mL (r=0.9999, n=5). The values of RSD (%) for the intra-day and inter-day precision ranged from 0.04 to 0.22 and 0.65 to 0.88%, respectively. The average of the recovery percentage ranged from 98.86 to 99.36%. The detection limit (DL) and quantitation limit (QL) for buprenorphine were 0.008 and 0.024 μg/mL, separately. The robustness of this method was also evaluated on the small fluctuations of pH in the mobile phase, the mobile phase compositions, and the flow rate. The results of stability studies showed the hydrolysis reaction of buprenorphine followed zero-order kinetics model in acidic and basic environment and followed first-order kinetics model in the presence of hydrogen peroxide. This analytical method was successfully applied to the determination of buprenorphine in transdermal patch and can be used for routine quality control work.

Ginger is one of the most frequently used ingredients in Chinese folk medicine and cooking. Ginger rhizome is used in treating/relieving appetite loss and motion sickness in western world. 6-Gingerol has been used as a marker substance of ginger . An HPLC analytical procedure of 6-gingerol was described. The correlation coefficients were greater than 0.999. The described HPLC procedure in this report has been validated and can be used to check 6-gingerol stability. It is also suitable for the preformulat ion study of ginger. The stabilities of ginger solution at different pHs were studied. The 6-gingerol contents in different preparations wer e evaluated.

This study was aimed to develop the new transdermal formulation to improve the permeability of buprenorphine. The apparent partition coefficients of buprenorphine were measured using the buffers at pH 1.2 to 10.0 as aqueous phase. The solubility of buprenorphine was 12.97 μg/mL in the 0.1 M phosphate buffer at pH 6.8. The influences of vehicles at different pH, adhesives, and permeation enhancers on the penetration of buprenorphine through nude mouse skin were investigated using the static Franz diffusion cells. The permeation parameter J(subscript ss) of buprenorphine increased along with the reduction of the pH of receptor fluid, and the vehicle at pH 6.8 was used in the following skin permeation studies. The pressure sensitive adhesives (PSA) including polyisobutylene (PIB), polystyrene-block-polyisoprene-block-polystyrene (SIS), and acrylic adhesives were evaluated. The permeability of buprenorphine was higher in the PIB or SIS adhesives than that in the acrylic adhesives under the condition without enhancer. When combined the enhancers with propylene glycol (PG) to improve the penetration of buprenorphine, the permeation-enhancing effects of enhancers were in the following order: lauric acid ＞ linolenic acid ＞ menthol ＞ oleic acid ＞ N-methyl-2-pyrrolidone (NMP) ＞ laurocapram ＞ glabridin. Finally, a matrix-type transdermal delivery system for buprenorphine was formulated using acrylic adhesive, PG, and lauric acid. The Jss parameter was 2.68±0.20 μg/cm^2/h and buprenorphine permeated across the nude mouse skin was 31.68%.

Neuropeptides control many physiological and behavioral processes, and so they are functionally important classes of cell-to-cell signaling molecules. Nowadays, the fall armyworm, Spodoptera frugiperda, is one of the most destructive agricultural pests in the world. In this study, we mined the publicly accessible genome assembly data for S. frugiperda, and the transcriptomic and proteomic data of the larval central nervous system (CNS) for putative neuropeptide-encoding, and subsequently we used these to anticipate a peptidome for this species. In essence, we could identify 57 orthologs of insect neuropeptides, including Allatotropin, CCHamide, Corazonin, pheromone biosynthesis activating neuropeptide, short neuropeptide F, Trissin, and Natalisin. Interesting features for S. frugiperda were the absence of genes coding for CNMamide, Elevein, and the differential evolution of ancestral neuropeptide genes such as adipokinetic corazonin-related peptide, adipokinetic hormone, Tachykinin, and Natalisin. In conclusion, our study provides the most complete neuropeptide description for the important pest S. frugiperda as a foundation to study the factors regulating insect growth, reproduction, and behavior. Second, we confirm that a comprehensive multi-omics analysis is necessary for the identification of neuropeptides. Finally, our data provide a reliable reference for other comparative studies in other insects beyond the supermodel insect of Drosophila melanogaster and the finding of potential candidates as selective for pests versus beneficial insects.

In this study, metalla-aromatic agents (MA) and a cluster of superparamagnetic iron oxide nanoparticles (SPIOs) were loaded inside a micellar carrier (Alkyl-PEI2k-PEG), resulting in MA/SPIOs@Alkyl-PEI2k-PEG nanoparticles (MASAs). The prepared MASAs with a photothermal transduction efficiency of 26.6% were also demonstrated as a potential photodynamic sensitizer to generate ROS effectively. Under the guidance of MRI/photoacoustic imaging, combined photothermal and photodynamic therapy achieved a synergistic anti-tumor effect, significantly improving the therapeutic efficacy of MASAs both in vitro and in vivo. This work shows that the developed MASAs are a potential theranostic agent for dual-modal imaging-guided cancer phototherapy.

Metal contamination of water bodies from industrial effluents presents a global threat to the aquatic ecosystem. To address this challenge, metal sequestration via adsorption onto solid media has been explored extensively. However, existing sorbent systems typically involve energy-intensive syntheses and are applicable to a limited range of metals. Herein, a sorbent system derived from physically cross-linked polyphenolic networks using tannic acid and ZrIV ions has been explored for high-affinity, broad-spectrum metal sequestration. The network formation step (gelation) of the sorbent is complete within 3 min and requires no special apparatus. The key to this system design is the formation of a highly stable coordination network with an optimized metal-ligand ratio (1.2:1), affording access to a major fraction of the chelating sites in tannic acid for capturing diverse metal ions. This system is stable over a pH range of 1-9, thermally stable up to ∼200 °C, and exhibits a negative surface charge (at pH 5). The sorbent system effectively sequesters 28 metals in single- and multielement model wastes, with removal efficiencies exceeding 99%. Furthermore, it is demonstrated that this system can be processed as membrane coatings, thin films, or wet gels to capture metal ions and that both the sorbent and captured metal ions can be regenerated or directly used as composite catalysts.

Soil colour can indicate soil physical, chemical and biological properties and processes, and is an important indicator for soil classification, soil quality evaluation and soil management. It varies in both horizontal and vertical dimensions, and thus regional maps of soil colour can reveal spatial patterns of these properties, processes, and indicators. However, although soil regions are sometimes named for their dominant soil colour, it is directly measured only at “point” support, i.e., during soil profile description, whereas it is desirable to know soil colour over the entire soilscape. To achieve this for China we used predictive soil mapping methods to produce soil colour maps (dry and moist colours) at 1 km2 grid cell size and over multiple depths from a consistent dataset of approximately 4 600 full profile descriptions taken as part of a national survey to define soil series in Chinese Soil Taxonomy, and a set of environmental covariates covering the national territory. The covariates characterized soil forming factors including climate, parent materials, terrain, vegetation, land surface water and thermal conditions. Soil colour descriptions in the Munsell system were extracted from the genetic horizon descriptions at the selected depths and converted to the sRGB and L*a*b* colour spaces. Dry and moist colour separates were not well-correlated in either space ( r 0.76 ). Random forest models were constructed in both spaces, for dry and moist colours separately. Models in sRGB space were moderately successful ( R 2 ≈ 0.43 , RMSE ≈ 26 / 255 ) at 5 cm, with success decreasing with depth. Models smoothed the colour space and thus did not predict the more extreme values or chromas, nor the rarer hues. Models in L*a*b* space were less successful. The fitted sRGB models were used to produce predictive maps over all of China. Regional patterns as well as local detail are clearly shown. Solar radiation, wind exposure, regolith thickness, and Landsat TM bands 7 and 5 contributed most to the predictions, followed by elevation, mean annual precipitation, terrain wetness index, air temperature seasonality, precipitation standard deviation and standard deviation of NDVI. These suggest pedological processes acting on the development of soil colours, including weathering of parent materials, oxidation-reduction chemistry and biochemistry of the decomposing of organic matter. This study shows that predictive methods from points using suitable covariates are an alternative to spatial predictions over map units from their representative profiles.

The diamondback moth Plutella xylostella is a serious pest of crucifers. It has high reproductive potential and is resistant to many insecticides. Typically, the last-instar larvae of P. xylostella, before pupation, move to the lower or outer plant leaves to make a loose silk cocoon and pupate inside for adult formation. To better understand this pivotal stage we studied the cocoon-spinning behavior of P. xylostella and measured three successive phases by video-recording, namely the selection of a pupation site, spinning a loose cocoon and padding the scaffold cocoon. Subsequently, we cloned three fibroin genes related to cocoon production, i.e., fibroin light chain (Fib-L), fibroin heavy chain (Fib-H), and glycoprotein P25. A spatio-temporal study of these three fibroin genes confirmed a high expression in the silk glands during the final larval instar silk-producing stage. In parallel, we did an exogenous treatment of the insect molting hormone 20-hydroxyecdysone (20E), and this suppressed fibroin gene expression, reduced the normal time needed for cocoon spinning, and we also observed a looser cocoon structure under the scanning electron microscope. Hence, we demonstrated that the expression levels of key genes related to the synthesis of 20E [the three Halloween genes Spook (Spo), Shadow (Sad), and Shade (Shd)] decreased significantly during spinning, the expression of the 20E receptor (EcR and USP) was significantly lower during spinning than before spinning, and that the expression levels of CYP18-A1 related to 20E degradation were significantly up-regulated during spinning. The significance of the cocoon and the effects of 20E on the cocoon-spinning behavior of P. xylostella are discussed.

Up-to-date maps of soil organic carbon (SOC) concentrations can provide vital information for monitoring global or regional soil C changes and soil quality. In this study, a national soil dataset collected in the 2010 s was applied to produce SOC maps of mainland China at soil depths of 0–5 cm, 5–15 cm, 15–30 cm, 30–60 cm, 60–100 cm and 100–200 cm. A stacking ensemble learning framework was utilized to take advantage of the optimal predictions from individual models. A voting-based ensemble learning model (VELM) was proposed with consideration of pedoclimatic zones. In this model, three machine learning models were separately trained for every pedoclimatic zone, and their predictions were selectively merged together. A weighted ensemble learning model (WELM), in which the parameterization considered all zones (i.e., the whole study area) simultaneously, was also trained for comparison. The overall R2 values of these two methods ranged from 0.16 to 0.57 and decreased with depth. Based on the independent validation, the R2 values ranged from 0.41 to 0.57 in the topsoil (0–5 cm, 5–15 cm and 15–30 cm). Overall accuracy metrics implied that the VELM and WELM yielded nearly the same prediction performances. However, model validation in the pedoclimatic zones showed that the VELM obviously outperformed the WELM, with the VELM generally improving the accuracy by 12.6%. Based on the independent validation, we also compared our predictions with other soil map products. Although the spatial patterns were similar, the predicted SOC maps outperformed two other products. The comparison of the two ensemble models should serve as a reminder that if new national or regional soil maps are generated, validation based on pedoclimatic zones or other soil-landscape units may be necessary before applying these maps.

Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases of rice worldwide. The aim of the present study was to elucidate the virulence structure of M. oryzae populations in Fujian Province, China, over the period 2006–2015. For this purpose, 456 M. oryzae isolates collected from diverse cultivars from eight rice cropping regions in Fujian were screened for the presence of 11 known avirulence genes: Avr-Pik, Avr-Pita1, Avr-Pita2, Avr-Pita3, PWL2, Avr1-CO39, ACE1, Avr-Piz-t, Avr-Pia, Avr-Pii and Avr-Pikm, with gene-specific molecular markers. The results showed that Avr-Pik and Avr-Pita3 occurred at the highest frequency (94.5% and 91.7%, respectively), while Avr1-CO39 and Avr-Pii were not detected. Further, the remaining avirulence genes occurred at frequencies ranging from 5.9% to 89.0%. Temporal population dynamics revealed that Avr-Pik was uniformly distributed in all 10 years, at frequencies of more than 87.5%. Spatial distribution analysis showed avirulence genes were...

A rapid and sensitive polymerase chain reaction (PCR) method was established for detection of mating types of Cochliobolus heterostrophus, the causal agent of southern corn leaf blight (SCLB). Two ...

A paddy soil chronosequence consisting of four profiles derived from Quaternary red clay (QRC) in Southern China with cultivation history from 0 to 300 years was studied to understand the underlying mechanisms and processes controlling the centennial scale Fe evolution during anthropedogenesis. We evaluated the chronosequencial changes in depth distribution of Fe oxides and Fe isotopic compositions. Results showed that paddy soil development on QRC over a centennial time scale caused increasing profile differentiation of Fe oxides and measurable Fe isotope fractionation. Total Fe and oxide bound Fe as well as the maximum Fe illuviation depth decreased as paddy soils age, leading to significant differences in morphological properties between paddy and non-paddy soils with the same parent material. Selective extractions showed that the weakly-bound, oxide-bound and silicate bound Fe corresponded to 4–18%, 49–81%, and 11–40% of the total Fe, respectively, and these proportions varied with both time and depth due to the redox-related Fe transformation and redistribution. δ56Fe values in the studied paddy soil chronosequence ranged from 0.05‰ to 0.26‰ and exhibited a strong negative correlation with the logarithm of total Fe concentrations, suggesting mass-dependent Fe isotope fractionation occurred as a result of the preferential removal of lighter Fe isotopes during Fe leaching loss under the predominant reducing conditions. However, the Fe isotopic ratio of a specific paddy soil horizon was a result of a complex interaction of different processes, which were summarized and interpreted in our proposed conceptual model of Fe evolution in terraced paddy soils. Further investigations of Fe isotope signatures in the soil-plant-water system with a combination of laboratory simulation and prediction of Fe isotope fractionation under different pedogenic processes are needed to evaluate the relative contribution of multiple processes to Fe isotope fractionation during anthropedogenesis of paddy soils.

Vinasse is the waste liquid of molasses fermentation for alcohol production from sugarcane mills. The adequate utilization and treatment for vinasse have received increasing attention. Among the alternatives considered for the reuse of vinasse, irrigation in sugarcane fields is most common solution. However, few researchers consider the impact on the soil fertility, soil heavy metals content and soil microbial diversity by long-term application of vinasse in the fields. In order to evaluate the cumulative impact arising from the long-term application of vinasse, different treatments, viz., (1) soils not irrigated with vinasse, (2) soil irrigated with vinasse for 2 years, (3) soil irrigated with vinasse for 7 years, (4) soil irrigated with vinasse for 13 years, (5) soil irrigated with vinasse for 18 years, have been applied to sugarcane fields in Shangsi County, Guangxi, China. The pH, organic matter, total and available N, P, K, the concentration of Cu, Pb, Cr, Zn, Ni, Cd and As, as well as the diversity of microbial community of the soil samples were determined. The results showed that after long-term irrigation by vinasse, soil acidification was observed, organic matter, N and K content increased, but no significant changes in the increase in P content were observed. The potential ecological risk of Cd, Cr, Pb, Zn, Cu, Ni and As was low, indicating that accumulation of heavy metals in the soil was negligible when long-term irrigation with vinasse was practiced. The diversity of microbial community expressed as relative abundance of the predominant species in irrigated soil was slightly reduced due to influence by the physicochemical properties of soil, especially soil pH. Consequently, the proper management of vinasse irrigation and periodic monitoring of soil quality parameters are required to ensure safe and long-term irrigation.

Southern corn leaf blight (SCLB) caused by Cochliobolus heterostrophus is a fungal disease that impacts production of corn in China. Fungicides have been the main strategy to manage SCLB. In this study, 276 isolates of C. heterostrophus from seven locations in Fujian Province of China were tested for sensitivity to three demethylation inhibitor (DMI) fungicides. The results indicated that most of the isolates of C. heterostrophus tested were exceptionally sensitive to the three DMI fungicides. Correlation analysis revealed positive association between propiconazole and diniconazole (r = 0.8145, P

Cephalotaxus sinensis is an endangered Tertiary relict tree endemic to China with high medicinal values. To contribute to its conservation genetics studies, its complete chloroplast (cp) genome was assembled using Illumina high-throughput sequencing technology in this study. The cp genome is 135,646 bp long with an asymmetric base composition (32.5% A, 17.6% C, 17.5% G and 32.4% T). It encodes a set of 113 unique genes (incl. 82 protein coding, 27 tRNA and 4 rRNA genes) with one of them (trnQ-UUG) being duplicated. Besides, 14 genes (atpF, ndhA, ndhB, petB, petD, rpl2, rpl16, rpoC1, rps12, rps16, trnA-UGC, trnG-UCC, trnI-GAU and trnK-UUU) possess a single intron, and another gene (ycf3) has a couple of introns. Phylogenetic analysis generally supported the current family-level taxonomy of the order Cupressales, and suggested that C. sinensis is closely related to the congeneric C. oliveri.

The development of tumor-targeting nanocarriers is critical important for effective treatment. The synthetic polyesters have demonstrated high potential for developing nanocarriers for cancer theranostics. Especially, the biocompatible and biodegradable polyester micelles have held great promise for cancer therapy and diagnosis, while some candidates have been translated into clinical applications or under clinical trial. In this review, we have provided the state-of-the-art of polyester micelles for drug delivery and cancer theranostics. In addition, we have summarized several major types of polyesters used in the biomedical fields, the current clinical achievements of polyester micelles and recent progresses of multi-functional polyester micelles for tumor molecular imaging and therapeutic applications.

Knowledge of soil carbon (C) distribution and its relationship with the environment can improve our understanding of its biogeochemical cycling and help to establish sound regional models of C cycling. However, such knowledge is limited in environments with complex landscape configurations. In this study, we investigated the vertical distribution and storage of soil organic carbon (SOC) and soil inorganic carbon (SIC) in the 10 representative landscapes (alpine meadow, subalpine shrub and meadow, mountain grassland, mountain forest, typical steppe, desert steppe, Hexi Corridor oases cropland, Ruoshui River delta desert, Alxa Gobi desert, and sandy desert) with contrasting bioclimatic regimes in the Heihe River Basin, Northwest China. We also measured the 87Sr/86Sr ratio in soil carbonate to understand the sources of SIC because the ratio can be used as a proxy in calculating the contribution of pedogenic inorganic carbon (PIC) to total SIC. Our results showed that SOC contents generally decreased with increasing soil depth in all landscapes, while SIC contents exhibited more complicated variations along soil profiles in relation to pedogenic processes and parent materials at the various landscapes. There were significant differences of C stocks in the top meter among different landscapes, with SOC storage ranging from 0.82 kg C/m2 in sandy desert to 50.48 kg C/m2 in mountain forest and SIC storage ranging from 0.19 kg C/m2 in alpine meadow to 21.91 kg C/m2 in desert steppe. SIC contributed more than 75% of total C pool when SOC storage was lower than 10 kg C/m2, and the proportion of PIC to SIC was greater than 70% as calculated from Sr isotopic ratio, suggesting the critical role of PIC in the C budget of this region. The considerable variations of SOC and SIC in different landscapes were attributed to different pedogenic environments resulted from contrasting climatic regimes, parent materials and vegetation types. This study provides an evidence for a general trade-off pattern between SOC and SIC, showing the compensatory effects of environmental conditions (especially climate) on SOC and SIC formation in these landscapes. This is largely attributed to the fact that the overall decrease in temperature and increase in precipitation from arid deserts to alpine mountains simultaneously facilitate the accumulation of SOC and depletion of SIC.

Plants play an important role in Silicon (Si) cycling of terrestrial ecosystems. However, how plant Si is related to soil Si translocation and transformation in subtropical areas with ample weatherable silicates and agricultural activities is largely unknown. Three typical watersheds with different cropland and forest configurations in subtropical China were selected to investigate the biomass of different plant species, including coniferous forest, bamboo and paddy, as well as the geochemical composition of soil, rock, vegetation and water. The main soil types are Lithic Udorthents, Lithic Dystrudepts and Typic Epiaquepts derived from granite. Si concentrations in rock, soil, plant and water, as well as Si cycling fluxes, were measured. The results show that although a large amount of Si is cycled by plants, weathering and runoff contribute similarly to, or even more significantly than, plant cycling. High Si bio-accumulators assimilate and return more Si than low Si bio-accumulators, and also cause more phytolith-Si to be added to the surface soil, which decreases desilification rate of surface soil. Agricultural activities increase silicate weathering. Stream water Si concentrations are not affected by plant Si cycling. Thus, both agricultural activities and plant species affect Si translocation. In contrast to results from strong tropical weathering environments, Si cycling by plants in this subtropical area with abundant weatherable silicates does not dominate Si loss from soil; rather, it promotes silicate weathering and controls Si redistribution in soil profiles.

A paddy soil chronosequence consisting of five profiles derived from calcareous marine sediments with cultivation history from 0 to 1000 years was studied to understand the underlying mechanisms and processes controlling the millennial scale Fe evolution. We evaluated the chronosequencial changes in depth distribution of Fe oxide contents and Fe isotopic compositions. Results showed that paddy soil evolution under the influence of periodic flooding and groundwater fluctuation resulted with time in variations of soil moisture regime and redox condition that control Fe mobilization, translocation and redistribution, leading to enhanced profile differentiation of Fe oxides and measurable Fe isotope fractionation. Total Fe and oxide bound Fe as well as their differentiation between surface and subsurface horizons increased as paddy soils age, leading to the formation of diagnostic horizons and features characterizing Fe distribution and redistribution. Selective extractions showed that the weakly-bound, oxide-bound and silicate bound Fe corresponded to 1–16%, 8–46%, and 52–91% of the total Fe, respectively, and these proportions varied with both time and depth due to the redox-related Fe transformation and translocation. δ56Fe values in the studied paddy soil chronosequence ranged from − 0.01‰ to 0.18‰ and exhibited a strong negative correlation with the logarithm of total Fe concentrations, suggesting mass-dependent Fe isotope fractionation occurred as a result of the preferential removal of lighter Fe isotopes during long-term paddy soil evolution under the predominant reducing conditions. However, the Fe isotopic ratio of a specific paddy soil horizon was a result of a complex interaction of different processes, which were summarized and interpreted in our proposed conceptual model. Comparison of Fe isotopic compositions in the worldwide soils demonstrated that Fe isotopes can evidence Fe transfer and pinpoint the factors and processes that control Fe mobilization and redistribution particularly in soils with changing moisture regimes and redox conditions. Our findings provide new insights into the behavior and geochemical cycle of Fe at the Earth's surface strongly affected by human activities and contributes to an improved understanding of how anthropedogenesis affects Fe evolution in the Earth's Critical Zone.