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Lipid-headgroup dehydration by DMSO, which should increase friction, is offset by both higher areal head-group density and by rigidity-enhancement of the lipid bilayers, both of which act to reduce frictional dissipation.

Trace detection based on surface-enhanced Raman scattering (SERS) has attracted considerable attention, and exploiting efficient strategies to stretch the limit of detection and understanding the mechanisms on molecular level are of utmost importance. In this work, we use ionic liquids (ILs) as trace additives in a protein-TiO2 system, allowing us to obtain an exceptionally low limit of detection down to 10-9 M. The enhancement factors (EFs) were determined to 2.30 × 104, 6.17 × 104, and 1.19 × 105, for the three systems: one without ILs, one with ILs in solutions, and one with ILs immobilized on the TiO2 substrate, respectively, corresponding to the molecular forces of 1.65, 1.32, and 1.16 nN quantified by the atomic force microscopy. The dissociation and following hydration of ILs, occurring in the SERS system, weakened the molecular forces but instead improved the electron transfer ability of ILs, which is the major contribution for the observed excellent detection. The weaker diffusion of the hydrated IL ions immobilized on the TiO2 substrate did provide a considerably greater EF value, compared to the ILs in the solution. This work clearly demonstrates the importance of the hydration of ions, causing an improved electron transfer ability of ILs and leading to an exceptional SERS performance in the field of trace detection. Our results should stimulate further development to use ILs in SERS and related applications in bioanalysis, medical diagnosis, and environmental science.

NLRP3 plays a pathogenic role in tumorigenesis by regulating innate and acquired immunity, apoptosis, differentiation, and intestinal microbes in tumors. In different tumors, NLRP3 plays different roles, and its mechanism is complex. Our research aimed to comprehensively investigated the role of NLRP3 in pan-cancers based on multi-omics data in the TCGA database. We found the expression of NLRP3 was changed in tumors compared with paired non-tumor specimens. Most types of tumors showed increased expression of NLRP3. Among them, the overexpressed NLRP3 in liver hepatocellular carcinoma (LIHC) and ovarian cancer (OV) indicated worse overall survival (OS). Further analysis also confirmed overexpressed NLRP3 in colon cancer (COAD) indicated a high probability of microsatellite instability (MSI) and low tumor mutational burden (TMB), which indicated a better response to immune checkpoint inhibitors (ICIs). We also analyzed the association between NLRP3, immune infiltration, and immune checkpoints. Interestingly, overexpression of NLRP3 was closely related to high infiltration of immune cells (T cells, B cells, etc.) and overexpressed immune checkpoints (PD-1, PD-L1, LAG3, etc.). These results demonstrated NLRP3 promoted immune escape in cancers. Finally, we investigated the expression of various immune checkpoints by treating NLRP3 inhibitor MCC950 during the co-culture of peripheral blood mononuclear cells (PBMC) and LIHC cell line Hep3B. We found MCC950 significantly repressed the expression of PD-L1 and LAG3, and promoted the apoptosis rate of Hep3B. In conclusion, our research comprehensive demonstrated the role of NLRP3 in pan-cancer, especially in LIHC. We confirmed inhibition of NLRP3 promoting the immune killing effect to cancer cells by repressing the expression of immune checkpoints.

Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the c ...

Background: Despite the various key functions of RBPs in posttranscriptional events, the mechanism of their influence on Wilms’ tumor has not been well elucidated. Therefore, we constructed the research to identify several RBPs related to Wilmes’ tumor progression and prognosis, for the better understanding of RBPs’ role in the occurrence and development of Wilmes’ tumor, and to provide effective reference targets for new drug development.Methods: A total of 127 samples of different clinical characteristics including gender, race and stage were selected from TARGET to carry out our study. After the gene functional enrichment pathways, univariate Cox regression analysis and lasso regression analysis were performed to test the prognostic effect of the differentially-expressed genes and establish the prognostic index . Further Cox regression analyses were utilized to identify the independence of our model and to analyze the relationship between our model and clinical parameters. What’s more, gene set enrichment analysis (GSEA) was also performed to elucidate the biological characteristics of genes involved in Wilms’ tumor. P< 0.05 was considered to be statistically significant.Results: 20 RBPs were statistically correlated with Wilms’ tumor. After the construction of a prognostic index , patients were divided into high-and low-risk scores group. Kaplan-Meier (K-M) analyses showed that patients with high risk scores possessed poorer survival probability than patients with low risk scores in both training group and test group. Furthermore, multivariate Cox regression analysis explored the relationship between our prognostic model and clinical parameters and confirmed that our model was an independent predicted factor for Wilms’ tumor. Conclusion: Our study clarifies the application of RBPs in the prognosis of Wilms’ tumor. We are confident that our risk scoring model can provide ideas for the development of new targets for broad-spectrum anticancer drugs and has great potential in clinical practice.

Objective. To investigate the value of neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and red blood cell distribution width (RDW) in evaluating the prognosis of children with severe pneumonia (SP). Methods. A retrospective analysis of the data of 91 children with SP admitted to our hospital from March 2018 to March 2021. According to the survival status after 28 days of treatment, all children were divided into the survival group (n = 59) and the death group (n = 32). The clinical data and laboratory indicators of the patients were recorded. Multivariate logistic regression was used to analyze the risk factors of prognosis, and the ROC curve was used to analyze the predictive value of each index. Results. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score and CURB-65 score of the death group were higher than those of the survival group ( P < 0.05 ). The RDW, NLR, PLR, and high-sensitivity C-reactive protein, procalcitonin blood lactic acid (Lac) of the death group, were higher than those of the survival group, and LYM was lower than the survival group ( P < 0.05 ). Multivariate regression analysis showed that APACHE II score, RDW, NLR, PLR, and Lac were all independent risk factors for poor prognosis in children with SP ( P < 0.05 ). The AUC of NLR, PLR, and RDW for evaluating the prognosis of children with SP were 0.798, 0.781, and 0.777, respectively. The sensitivity was 56.25%, 90.63%, and 56.25%, respectively, and the specificity was 89.83%, 55.93%, and 91.53%, respectively. The AUC of NLR, PLR, and RDW combined to evaluate the prognosis of children with SP was 0.943. When the best cut-off value was 0.8528, the sensitivity was 93.75%, and the specificity was 91.53%. Conclusion. NLR, PLR, and RDW have certain predictive value for the prognosis of children with SP; the combination of the three indicators has a higher value in evaluating the prognosis of children with SP, which can better guide the prognostic treatment.

Abstract During the last several decades, wetlands are losing their ecological functions due to increasing anthropogenic loads. One of these functions is the ability to bind elements forming geochemical barriers. The research aimed to study the geochemical conditions of natural wetlands and flooded paddy fields (artificial wetlands) in the Ganjiang River basin to trace geochemical barriers. The research approach was based on a comprehensive analysis of water and aqueous extracts from bottom sediments and paddy soils, including chemical and mineral composition. The samples were collected in November 2019, during the dry season at the end of harvesting. Chemical analysis was performed using standard methods for natural substances: titrimetry, photometry, ionic chromatography, high-temperature oxidation, ICP-MS, and ICP-AES. The mineral composition of the soils and sediments was determined by XRD. It was found that the main physicochemical characteristics (TDS, pH, main component concentrations) of the natural wetland water correspond to the surface water of the study area, whereas the irrigation water is similar to shallow groundwater. The content of trace elements in the irrigation water is higher than in the natural wetland water. Generally, the trace element composition of the natural wetland water corresponds to the geochemical background of the study area. Analysis of the mineral and chemical composition of the paddy soils and sediments indicates the geochemical barriers that accumulate a wide range of elements. In the natural wetland, the geochemical barrier is likely associated with a decrease in oxygen content and advective transport rate in the sediments, whereas in the paddy fields, the precipitation of clay minerals in the soil profile forms the geochemical barrier related to a decrease in filtration properties and advection–diffusion transport. Graphic abstract

BackgroundRNA-binding proteins (RBPs), the ubiquitous regulators that can bind to RNA, mediate the function of RNA in the process of its maturation, translation, transport and localization [1, 2]. Despite the various key functions of RBPs in posttranscriptional events, the mechanism of their influence on Wilms’ tumor has not been well elucidated. So we construct the research to identify several RBPs related to Wilmes’ tumor progression and prognosis, for the better understanding of RBPs’ role in the occurrence and development of Wilmes’ tumor, and to provide effective reference targets for new drug development.MethodsA total of 127 samples of different clinical characteristics including gender, race and stage were selected from TCGA to carry out our study. After the gene functional enrichment pathways, univariate Cox regression analysis and lasso regression analysis were performed to test the prognostic effect of the differentially-expressed genes and establish the prognostic index . Further Cox regression analyses were utilized to identify the independence of our model and to analyze the relationship between our model and clinical parameters. What’s more, gene set enrichment analysis (GSEA) was also performed to elucidate the biological characteristics of genes involved in Wilms’ tumor. P< 0.05 was considered to be statistically significant.Results26 RBPs were statistically correlated with Wilms’ tumor. After the construction of a prognostic index , patients were divided into high-and low-risk scores group. Kaplan-Meier (K-M) analyses showed that patients with high risk scores possessed poorer survival probability than patients with low risk scores in both training group and test group. Furthermore, multivariate Cox regression analysis explored the relationship between our prognostic model and clinical parameters and confirmed that our model was an independent predicted factor for Wilms’ tumor. ConclusionOur study clarifies the application of RBPs in the prognosis of Wilms’ tumor. We are confident that our risk scoring model can provide ideas for the development of new targets for broad-spectrum anticancer drugs and has great potential in clinical practice.Trial registrationretrospectively registered

The TiO2 nanotube pattern with features down to 20nm (TN20) is highly and efficiently resistant to fibrinogen and S. aureus attachment. The ability of TN20 to resist biofouling adsorption, is due to low biofouling-surface adhesion force that determines the initial biofouling attachment, as well as the low friction coefficient that enables a complete removal of biofouling from a low-adhesive 'repelling' TN20 substrate under fluid flow. By grafting PEG molecules onto TN20, a significantly higher S. aureus cells attachment was observed, because of the stronger adhesion forces originated from the deformation of the soft PEG coatings. The complete interaction of S. aureus on structure-free dense TiO2 (DT), yields larger contact area and thus higher adhesion force than on any other TiO2 surfaces, resulting in a high coverage of bacteria. The existing high friction coefficient of S. aureus on TN80 (TiO2 with 80nm nanotubular size) and TN80-P (PEG-modified TN80), due to the much greater surface roughness, would contribute to the immobilization of biofouling on the surface under fluid flow, even though the two surfaces exhibit low adhesion forces. The analysis of adhesion and friction forces manipulated by TiO2 nanotubular topography and posted PEG patterns, advances our understanding of the mechanisms by which nanotopography patterned surfaces reduce biofouling attachment.

Jiangxi Province is one of the regions where geothermal water is widely distributed in China, with discovered 96 hot springs and over 30 thermal water boreholes. Eleven geothermal water samples were collected and analyzed for hydrochemical and isotopic characteristics to distinguish the sources of geothermal water in Jiangxi Province, SE-China. Results showed that water temperatures varied from 32.0 to 80.8 °C with an average of 53.4 °C and the dominated compositions are Na-HCO3 type. The hydrogeochemical characteristics as well as isotopic compositions suggest the meteoric origin of geothermal water with recharge altitudes in the range of 400-995 m. Mixing with cold groundwater influences the hydrochemistry of geothermal water. This study furthers the understanding of sources of geothermal water and provides a theoretical basis for better exploitation of geothermal water in the province.

The hydrochemical and stable hydrogen and oxygen isotope compositional characteristics of surface and shallow groundwaters in the vicinity of HK nuclear power plant in Jiangxi Province of China. Dissolved oxygen (DO) contents of shallow groundwaters range between 1.75 to 19.40 mg/L, with variations related to well depth, groundwater level, and oxidation-reduction potential. Respective ranges of δD and δ18O (‰ VSMOW) in shallow groundwaters are -40.7 to -24.9 and -6.71 to -5.40, with average values of -31.8 and -5.87. The δD-δ18O relationship for the study area is δD = 8.3δ18O +16.8, indicating that atmospheric precipitation is the major recharge source of shallow groundwaters.

As a novel chemical engineering unit operation, membrane separation has many advantages such as high efficiency and energy saving. Recently, at nanoscale, the increasingly anomalous phenomena of ultra-fast flux and breaking the tradeoff between flux and selectivity are found in membrane separations (such as pervaporation, reverse osmosis, nano-filtration, etc.), which promote considerable attentions. However, traditional models or mechanisms fail to explain these phenomena or to predict the behavior. The main reason of this is that when the size of systems shrinks to nanoscale, the intermolecular forces between the fluids and membrane pore wall (including primarily steric interactions/hydration, van der Waals interactions and electrostatic interactions) have become the most prominent ones in nanoconfined systems, which make significant contributions to mass-transfer and engender unique performance. The relevant mass-transfer theories especially under nanoconfinement lacks common mass-transfer mechanism and controlling methods for these abnormal phenomena on its mass-transfer, severely restricting the design and development of related membrane materials. To quantitatively describe the nanoconfined membrane process, a universal theoretical framework for nanoconfined mass-transfer is needed and then the contributions of various influencing factors at nanoscale to the flux and selectivity should be illustrated quantitatively. In this review, we first analyzed the challenges of classical mass-transfer models in the confinement conditions, such as solution-diffusion model to dense membrane. The main problem can be attributed to that these models in essence describe an equilibrium state plus a dynamic process, which not includes the interfacial influence. Secondly, we explored the application of non-equilibrium thermodynamics linearization method in establishing the mass-transfer model under nanoconfinement. We simplified the interfacial phenomenon to assume that system located at a distance close to interface can be regarded as a microelement and its deviation from equilibrium remained in the linear region. We established a model to describe nano- and micro-interfacial transfer confined in a complex structure, using CO2 separation by ionic liquids as an example, assuming that the transfer in phase interface comprised two steps (surface reaction and diffusion) in the same phase. The mass-transfer model on the basis of linear non-equilibrium thermodynamics was proven to decouple reaction and transfer more effectively for achieving process intensification by adjusting easy-to-control factors, compared with the classical solution-diffusion model. Thirdly, the factors affecting the behavior of the confined fluid molecules were so complex that it was difficult to do single-factor analysis and to determine controlling factors. Related advances on the analysis of the influencing factor for nanoconfined mass-transfer were further explored. We evaluated the effects of the influencing factors for water molecules transfer in various nanochannels or nanotubes, including pore size, pore wall hydrophilicity, pore geometrical shape and pore mouth modification, based on the numerous results derived from molecular simulation and experimental method. Finally, we had a brief conclusion and summarized the development directions. (1) Linear non-equilibrium thermodynamics method has great potential in the modeling of mass-transfer at nanoscale. (2) Experimentally synthesizing ordered nanochannel material should be encouraged to build a platform for comparison of the factor analysis results from molecular simulation and experiment. (3) The original experimental characterization methods are expected to be developed to probe the intermolecular interactions quantitatively.

The use of graphene oxide (GO) nanosheets for functional enzyme support has attracted intensive interest owing to their unique planar structure and intriguing physical and chemical properties. However, the detailed effects of the interface properties of GO and its functionalized derivatives on active biomolecules are not well understood. We immobilize nuclease P1, a common industrial nucleic acid production enzyme, on pristine and amino poly(ethylene glycol) (PEG-NH2) modified GO nanosheets with interface property heterogeneity using two approaches, physical adsorption and chemical crosslinking. It is demonstrated that nuclease P1 could be stable immobilized on the surface of pristine GO by physical adsorption and on the edge of modified GO nanosheets by chemical crosslinking. The resultant loading capacity of nuclease P1 on pristine GO is as high as 6.45mg/mg as a consequence of strong electrostatic and hydrophobic interactions between the enzyme and carrier. However, it is determined that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on PEG-NH2-modified GO are obviously improved compared to those of the enzyme immobilized on pristine GO. The enhanced catalytic behavior demonstrates that GO and its derivatives have great potential in efficient biocatalytic systems.

Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the combination of the adhesion forces and the molecular interaction measured with AFM. Cytochrome c (Cyt C) interacting effectively with TiO

This study was performed in the Linshui River Watershed to explore the contents of heavy metals in river water, their species, and health risks. The test results show that the contents of arsenic (As), chromium (Cr), copper (Cu), uranium (U), and thorium (Th) are relatively low and below the limit of class III of the environmental quality standards for surface water. According to the analysis through PHREEQC (version 2.18), the main species of As, Cr, Cu, U, and Th are H2AsO4− and HAsO42−, HCrO4−, Cr2O72− and CrO42−, Cu2+, CuSO4 and CuCO3, UO2CO3, (UO2)2CO3(OH)3−, and UO2(CO3)22−, Th(OH)4, Th(OH)22+, and Th(OH)3+, respectively. Health risk assessment demonstrates that the average total risk value is 5.68 × 10−5 year−1, which is higher than the maximum acceptable level of 5.05 × 10−5 year−1 recommended by International Commission on Radiological Protection (ICRP). Moreover, the average of total radionuclide risk (U and Th) is calculated to be 7.85 × 10−9 year−1, which is five orders of magnitude lower than the standard value of 5.0 × 10−4 year−1. The health risk of chemical non-carcinogenic (Cu) is lower than that of chemical carcinogenic (As and Cr). Human health risk values descend in the order of Cr, As, U, Th, and Cu. Therefore, As and Cr in the study area are labeled as the priority pollutants.

The TiO

The research is devoted to the analysis of the changes in the chemical composition of shallow groundwater within the agricultural landscapes of the Poyang Lake area taking into account the peculiarities of soil composition. The analysis is based on field data collected during 2011–2017 by the sampling of the shallow groundwater from the private and public wells and adjoining soils. Correlations between the content of the N-compounds and the Eh values in autumn as well as a relationship of the NH4+ concentration with the DOC content reflect the processes of the organic matter transformation in the aquifer. Correlations between the N content in the upper soil horizon and the concentrations of the N-compounds in the shallow groundwater indicate a strong connection of the origin of the groundwater chemical composition with the soil composition.

Because of water shortages, the Xiaodian area in northern China had a long history of sewage irrigation. To study the distribution of antibiotics in the vadose zone, a sewage sample and 5 soil profiles were collected and analyzed. Macrolides and Fluoroquinolones were the main antibiotics observed in the shallow vadose zone. The contents of antibiotics in the soil profile nearby the sewage irrigation area were 2-3 times greater than in the groundwater irrigation area, indicating that sewage irrigation has had a significant impact on the contents of antibiotics in the soil. The elevation of antibiotic contents during the wet season is likely related to the fluctuating water level within the shallow vadose zone. The distribution of antibiotics is influenced by the flow direction of irrigation water. Moreover, the possibility of introducing antibiotics into the soil of the shallow vadose via the lateral recharge of sewage in the Beizhang Drainage Canal can not be excluded. Approximately 50 % of Fluoroquinolones were reduced in the upper 50 cm of the soil zone and 70 % at 80 cm depth. Tetracyclines may have experienced significant lateral migration. Macrolides and Sulfonamides (SMs) have similar soil profile distributions, with a concentration decrease down to 20 cm depth.

The Poyang Lake basin in the Jiangxi province of China has been exposed to nitrate pollution caused by irrigation practices, leading to high groundwater nitrate concentration. Eight groundwater samples were collected from shallow wells for hydrochemical, bacterial diversity, and community structure analysis in November 2017. Shallow groundwaters of the basin are weakly acid and in an oxidizing state, with EC ranging from 87.6 to 279.5 µS/cm and TDS varying between 53 to 344 mg/L and averaging of 164 mg/L. The NO3-N form is the dominant nitrogen species in groundwater, with сoncentrations of NO3-N, NO2-N and NH4-N ranging between 2.5 to 164 mg/L, 0.01 to 0.10 mg/L, Denitratisoma and Sulfuritalea detected in low-nitrate groundwater suggest that these bacteria are capable of denitrification in anaerobic groundwater environment. Bacterial populations Flavobacteria and Cytophagia in high-nitrate groundwater are common in the s wetlands examined and likely capable of nitrification.

An effective and low-cost in-situ geological filtration system was developed to treat arsenic-contaminated groundwater in remote rural areas. Hangjinhouqi in western Hetao Plain of Inner Mongolia, China, where groundwater contains a high arsenic concentration, was selected as the study area. Fe-mineral and limestone widely distributed in the study area were used as filter materials. Batch and column experiments as well as field tests were performed to determine optimal filtration parameters and to evaluate the effectiveness of the technology for arsenic removal under different hydrogeochemical conditions. A mixture containing natural Fe-mineral (hematite and goethite) and limestone at a mass ratio of 2:1 was found to be the most effective for arsenic removal. The results indicated that Fe-mineral in the mixture played a major role for arsenic removal. Meanwhile, limestone buffered groundwater pH to be conducive for the optimal arsenic removal. As(III) adsorption and oxidation by iron mineral, and the formation of Ca-As(V) precipitation with Ca contributed from limestone dissolution were likely mechanisms leading to the As removal. Field demonstrations revealed that a geological filter bed filled with the proposed mineral mixture reduced groundwater arsenic concentration from 400 μg/L to below 10 μg/L. The filtration system was continuously operated for a total volume of 365,000L, which is sufficient for drinking water supplying a rural household of 5 persons for 5 years at a rate of 40 L per person per day.

Hangjinhouqi is one of the most serious endemic arsenic and fluorosis areas in Hetao Plain, China. Groundwater samples (n=97) and two sediment cores issued from boreholes were collected to characterize the hydrogeochemistry of groundwater and sediment lithology of aquifers. Results showed that arsenic and fluoride content in groundwater range from 1 to 1093μg/L and from 0.30 to 6.01mg/L, respectively. The highest concentrations are mainly found in the flat areas of the Yin Mountains. As and F are not correlated, suggesting that their origin and/or geochemical processes leading to their release to groundwater are different. Between 15 and 45m of depth, both arsenic and fluoride are more easily released into groundwater. The external environment of high As and high F groundwater formation consisted of a lake-based geographical environment in a long term and closed geological structure, arid and semi-arid climatic conditions, as well as hydrogeological characteristics.

Twenty groundwater samples and two surface water samples were collected to determine the occurrence and distribution of iodine and fluoride in groundwater in the area of Hangjinhouqi, the Hetao Plain, Inner Mongolia. Currently, 65% and 50% of samples exceeded the Chinese standard (I=150 μg/L, F=1 mg/L) for drinking water for iodine and fluoride, respectively. No correlation has been shown between I and F, although the spatial distribution of high iodine and high fluoride groundwater samples overlaps, with 80% of the high fluoride groundwater samples located in the high iodine areas. Different enrichment mechanisms of fluoride and iodine are involved. Water-rock interaction processes are at the origin of fluoride rich-groundwater, whereas evaporation of shallow groundwater and the oxidation by microorganisms of elevated organic matter content in deep groundwater contribute to the enrichment of iodine.

The use of graphene oxide (GO) nanosheets for functional enzyme support has attracted intensive interest owing to their unique planar structure and intriguing physical and chemical properties. However, the detailed effects of the interface properties of GO and its functionalized derivatives on active biomolecules are not well understood. We immobilize nuclease P1, a common industrial nucleic acid production enzyme, on pristine and amino poly(ethylene glycol) (PEG-NH2) modified GO nanosheets with interface property heterogeneity using two approaches, physical adsorption and chemical crosslinking. It is demonstrated that nuclease P1 could be stable immobilized on the surface of pristine GO by physical adsorption and on the edge of modified GO nanosheets by chemical crosslinking. The resultant loading capacity of nuclease P1 on pristine GO is as high as 6.45mg/mg as a consequence of strong electrostatic and hydrophobic interactions between the enzyme and carrier. However, it is determined that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on PEG-NH2-modified GO are obviously improved compared to those of the enzyme immobilized on pristine GO. The enhanced catalytic behavior demonstrates that GO and its derivatives have great potential in efficient biocatalytic systems.

Hetao Basin, an inland-arid/semi-arid basin, is well known for the widely distribution of high arsenic groundwater and the serious local arseniasis causing by drinking high arsenic groundwater. Shallow groundwater in the basin generally occurs in the Quaternary alluvial, alluvial-pluvial, and fluvial-lacustrine aquifers, which are unconfined or leaky-confined. In this study, soil samples, surface water and groundwater samples were taken from Hetao Basin to analyse the occurrence and the distribution of arsenic in water and soil environments in this inland-arid/semi-arid basin. This study will provide a scientific basis for protect the safety of water supply in high arsenic groundwater areas.

The Xiaodian sewage irrigation area in northern China has a long history of sewage irrigation. The surface water and groundwater samples were collected and analyzed in this region. All the 25 kinds of antibiotics have been detected in the surface water in this study area. The order of average detection frequency is Macrolides (MLs, 98.2%) > Fluoroquinolones (FQs, 91.3%) > Tetracyclines (TCs, 87.5%) > Sulfonamides (SMs, 75.0%). The sample with the highest concentration of antibiotics (730.19 ng/L) is located at Taiyu Drainage Canal while that with the lowest concentration (245.93 ng/L) at Xiaohe River. The type and concentration of antibiotics in SW-3 and SW-4 were almost the same, indicating the measures to prevent canal banks from seepage were able to retard their transport into the soil and groundwater system via lateral recharge. Along the Beizhang Drainage Canal, the sewage from the swine farm, the cow farm, the irrigation field and domestic usage were all discharged into the canal, so the concentration kept increasing. Along the down gradient direction of Taiyu Drainage Canal, the concentration decreased. Transport of the contaminants via lateral recharge due to lack of seepage prevention measures, therefore, poses a potential threat to the soil-groundwater system. 15 of 25 kinds of antibiotics were detected in the groundwater. The detection frequency was lower than other study areas in China. The concentrations ranged from 2.75 ng/L to 114.38 ng/L with the average concentration of 27.60 ng/L.