Influences of shallow groundwater depth on N2O diffusion along the soil profile of summer maize fields in North China Plain.

The emissions of nitrous oxide (N2O) from agricultural fields are a significant contribution to global warming. Understanding the mechanisms of N2O emissions from agricultural fields is essential for the development of N2O emission mitigation strategies. Currently, there are extensive studies on N2O emissions on the surface of agricultural soils, while studies on N2O fluxes at the interface between the saturated and unsaturated zones (ISU) are limited. Uncertainties exist regarding N2O emissions from the soil-shallow groundwater systems in agricultural fields. In this study, a three-year lysimeter experiment (2019-2020, 2022) was conducted to simulate the soil-shallow groundwater systems under four controlled shallow groundwater depth (SGD) (i.e., SGD = 40, 70, 110, and 150 cm) conditions in North China Plain (NCP). Weekly continuous monitoring of N2O emissions from soil surface, N2O concentration in the shallow groundwater and the upper 10 cm of pores at the ISU, and nitrogen cycling-related parameters in the soil and groundwater was conducted. The results showed that soil surface N2O emissions increased with decreased shallow groundwater depth, and the highest emissions of 96.44 kg ha-1 and 104.32 kg ha-1 were observed at G2 (SGD = 40 cm) in 2020 and 2022. During the observation period of one maize growing season, shallow groundwater acted as a sink for the unsaturated zone when the groundwater depth was 40 cm, 70 cm, and 110 cm. However, when SGD was 150 cm, shallow groundwater became a source for the unsaturated zone. After fertilization, the groundwater in all treatment plots behaved as a sink for the unsaturated zone, and the diffusion intensity decreased with increasing SGD. The results would provide a theoretical basis for cropland water management to reduce N2O emissions.

Non-negligible N2O emission hotspots: Rivers impacted by ion-adsorption rare earth mining.

Rare earth mining causes severe riverine nitrogen pollution, but its effect on nitrous oxide (N2O) emissions and the associated nitrogen transformation processes remain unclear. Here, we characterized N2O fluxes from China's largest ion-adsorption rare earth mining watershed and elucidated the mechanisms that drove N2O production and consumption using advanced isotope mapping and molecular biology techniques. Compared to the undisturbed river, the mining-affected river exhibited higher N2O fluxes (7.96 ± 10.18 mmol m-2d-1 vs. 2.88 ± 8.27 mmol m-2d-1, P = 0.002), confirming that mining-affected rivers are N2O emission hotspots. Flux variations scaled with high nitrogen supply (resulting from mining activities), and were mainly attributed to changes in water chemistry (i.e., pH, and metal concentrations), sediment property (i.e., particle size), and hydrogeomorphic factors (e.g., river order and slope). Coupled nitrification-denitrification and N2O reduction were the dominant processes controlling the N2O dynamics. Of these, the contribution of incomplete denitrification to N2O production was greater than that of nitrification, especially in the heavily mining-affected reaches. Co-occurrence network analysis identified Thiomonas and Rhodanobacter as the key genus closely associated with N2O production, suggesting their potential roles for denitrification. This is the first study to elucidate N2O emission and influential mechanisms in mining-affected rivers using combined isotopic and molecular techniques. The discovery of this study enhances our understanding of the distinctive processes driving N2O production and consumption in highly anthropogenically disturbed aquatic systems, and also provides the foundation for accurate assessment of N2O emissions from mining-affected rivers on regional and global scales.

Leaf photosynthetic pigment as a predictor of leaf maximum carboxylation rate in a farmland ecosystem.

The leaf maximum rate of carboxylation (Vcmax) is a key parameter of plant photosynthetic capacity. The accurate estimation of Vcmax is crucial for correctly predicting the carbon flux in the terrestrial carbon cycle. Vcmax is correlated with plant traits including leaf nitrogen (Narea) and leaf photosynthetic pigments. Proxies for leaf chlorophyll (Chlarea) and carotenoid contents (Cararea) need to be explored in different ecosystems. In this study, we evaluated the relationship between leaf maximum rate of carboxylation (scaled to 25°C; Vcmax25) and both leaf Narea and photosynthetic pigments (Chlarea and Cararea) in winter wheat in a farmland ecosystem. Our results showed that Vcmax25 followed the same trends as leaf Chlarea. However, leaf Narea showed smaller dynamic changes before the flowering stage, and there were smaller seasonal variations in leaf Cararea. The correlation between leaf Vcmax25 and leaf Chlarea was the strongest, followed by leaf Cararea and leaf Narea (R2 = 0.69, R2 = 0.47 and R2 = 0.36, respectively). The random forest regression analysis also showed that leaf Chlarea and leaf Cararea were more important than leaf Narea for Vcmax25. The correlation between leaf Vcmax25 and Narea can be weaker since nitrogen allocation is dynamic. The estimation accuracy of the Vcmax25 model based on Narea, Chlarea, and Cararea (R2 = 0.75) was only 0.05 higher than that of the Vcmax25 model based on Chlarea and Cararea (R2 = 0.70). However, the estimation accuracy of the Vcmax25 model based on Chlarea and Cararea (R2 = 0.70) was 0.34 higher than that of the Vcmax25 model based on Narea (R2 = 0.36). These results highlight that leaf photosynthetic pigments can be a predictor for estimating Vcmax25, expanding a new way to estimate spatially continuous Vcmax25 on a regional scale, and to improve model simulation accuracy.

Pollution caused by mining reshaped the structure and function of bacterial communities in China's largest ion-adsorption rare earth mine watershed.

Ion-adsorption rare earth mining results in the production of high levels of nitrogen, multiple metals, and strong acidic mine drainage (AMD), the impacts of which on microbial assembly and ecological functions remain unclear. To address this knowledge gap, we collected river sediments from the watershed of China's largest ion-adsorption rare earth mine and analyzed the bacterial community's structure, function, and assembly mechanisms. Results showed that bacterial community assembly was weakly affected by spatial dispersion, and dispersal limitation and homogeneous selection were the dominant ecological processes, with the latter increasing with pollution gradients. Bacterial alpha diversity decreased with pollution, which was mainly influenced by lead (Pb), pH, rare earth elements (REEs), and electrical conductivity (EC). However, bacteria developed survival strategies (i.e., enhanced acid tolerance and interspecific competition) to adapt to extreme environments, sustaining species diversity and community stability. Community structure and function showed a consistent response to the polluted environment (r = 0.662, P = 0.001). Enhanced environmental selection reshaped key microbial-mediated biogeochemical processes in the mining area, in particular weakening the potential for microbial denitrification. These findings provide new insights into the ecological response of microbes to compound pollution and offer theoretical support for proposing effective remediation and management strategies for polluted areas.

Effect of Lianhua Qingwen capsules on the positive rate of COVID-19 close contacts: A retrospective analysis of a large-scale population-based cohort study.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is still spreading worldwide. COVID-19 close contact is a key point of this epidemic. However, no medication is now available for close contact. This study aims to evaluate the beneficial effect and safety of the Lianhua Qingwen capsule (LHQW) on COVID-19 close contacts via a large, retrospective cohort study. METHODS: A total of 25,002 close contacts from 199 quarantine sites in Changchun, Jilin, who underwent medical observation, were included. The information about these close contacts were collected for further epidemiological research. Moreover, subjects were divided into an exposure group (LHQW group, oral, 4 capsules/time, t.i.d.; 18,579 subjects) and a non-exposure group (control group; 6,423 subjects). Inverse probability of treatment weighting (IPTW) with propensity score was employed to evaluate the positive rate of the SARS-CoV-2 nucleic acid test in nasal and throat swabs confirmed by polymerase chain reaction (PCR). RESULTS: A total of 22,975 subjects were included in the analysis, 17,286 cases in the LHQW group and 5,689 cases in the control group. The positive rate of nucleic acid testing in the LHQW group was 5.12%, and that in the control group was 9.70% before the adjustment of IPTW of the propensity score; the difference between the two groups was -4.58% (95% CI -5.44- -3.77%, p <  0.001). After adjusting IPTW, the positive rate of nucleic acid testing in the LHQW group and the control group was 5.10% and 9.80%, respectively; the difference between the two groups was -4.70% (95% CI -5.18- -4.23, p < 0.001). The conclusions before and after the IPTW adjustment were consistent. No test drug-related adverse reactions were observed during the study period. CONCLUSION: LHQW has a beneficial effect and safety on the close contacts of SARS-CoV-2 who are under medical observation at the quarantine sites and can be used as an optional drug for those close contacts.

Posture optimization in swimming based on sports mechanics / Otimização da postura na natação baseada na mecânica esportiva / Optimización de la postura en la natación basada en la mecánica deportiva

ABSTRACT Introduction Speed and posture are two determining factors for the success of swimmers. Posture optimization can make athletes' actions more standardized and improve their speed at a competitive level. Objective Explore the optimization of swimming posture based on sports mechanics. Methods In the controlled experiment, the control group was given routine training, while the experimental group was given sport mechanics-based swimming posture optimization training. A duration of 60 minutes daily, three times a week. The experiment was completed in 6 weeks. Data by computerized cinematography were extracted using the reflective marking ball technique. Its mechanical motion and time consumption characteristics were collected before and after the experiment, cataloged, compared, and discussed statistically. Results Daily and posture optimization training can improve athletes' body extension range. The effect of the experimental group in improving the range of body extension was shown to be greater than the standard training and slightly greater than the daily training by shortening the action time. Conclusion The posture optimization scheme for swimming based on sports mechanics can improve athletes' extension range and speed. Physical education teachers and coaches should further optimize and promote the swimming posture optimization scheme to improve the performance of their athletes. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução Velocidade e postura são dois fatores determinantes para o sucesso dos nadadores. A otimização da postura pode não apenas tornar as ações dos atletas mais padronizadas como também pode melhorar a sua velocidade em um nível competitivo. Objetivo Explorar a otimização da postura de natação baseada na mecânica esportiva. Métodos No experimento controlado, o grupo de controle efetuou o treinamento de rotina, enquanto ao grupo experimental foi adicionado o treinamento de otimização da postura de natação baseado na mecânica esportiva. Numa duração de 60 minutos diários, três vezes por semana, o experimento foi completado em 6 semanas. Dados por cinematografia computadorizada foram extraídos utilizando a técnica da bola refletiva de marcação. Suas características mecânicas de movimento e características de consumo de tempo foram coletadas antes e depois do experimento, catalogadas, comparadas e discutidas estatisticamente. Resultados Tanto o treinamento diário quanto o treinamento de otimização da postura podem melhorar o alcance da extensão corporal dos atletas. O efeito do grupo experimental em melhorar o alcance da extensão corporal demonstrou-se superior ao do treinamento padrão, sendo ligeiramente maior do que o do treinamento diário encurtando o tempo de ação. Conclusão O esquema de otimização da postura para natação baseado na mecânica esportiva pode efetivamente melhorar a faixa de extensão e a velocidade dos atletas. Os professores e treinadores de educação física devem otimizar e promover ainda mais o esquema de otimização da postura de natação, visando melhorar o desempenho de seus esportistas. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción La velocidad y la postura son dos factores determinantes para el éxito de los nadadores. La optimización de la postura no sólo puede hacer que las acciones de los atletas sean más estandarizadas, sino que también puede mejorar su velocidad a nivel competitivo. Objetivo Explorar la optimización de la postura de natación basada en la mecánica deportiva. Métodos En el experimento controlado, el grupo de control realizó un entrenamiento rutinario, mientras que al grupo experimental se le añadió un entrenamiento de optimización de la postura de natación basado en la mecánica deportiva. Con una duración de 60 minutos diarios, tres veces por semana, el experimento se completó en 6 semanas. Los datos de la cinematografía computarizada se extrajeron mediante la técnica de la bola de marcado reflectante. Sus características de movimiento mecánico y de consumo de tiempo fueron recogidas antes y después del experimento, catalogadas, comparadas y discutidas estadísticamente. Resultados Tanto el entrenamiento diario como el de optimización de la postura pueden mejorar el rango de extensión corporal de los atletas. El efecto del grupo experimental en la mejora del rango de extensión corporal se mostró superior al entrenamiento estándar, y ligeramente superior al entrenamiento diario al acortar el tiempo de acción. Conclusión El esquema de optimización de la postura para la natación basado en la mecánica deportiva puede mejorar eficazmente el rango de extensión y la velocidad de los atletas. Los profesores de educación física y los entrenadores deben seguir perfeccionando y promoviendo el esquema de optimización de la postura de natación para mejorar el rendimiento de sus deportistas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Survival benefit of primary and metastatic tumor resection for colon cancer with liver metastases: A population based, propensity score-matched study.

Background: Colon cancer remains one of the most common malignancies and we aimed to evaluate whether surgery has an effect on the survival of metastatic colon patients. Methods: We analyzed 7,583 metastatic colon patients from the Surveillance, Epidemiology, between January 2010 and December 2015. Using Cox proportional hazards models and Kaplan-Meier curves, the overall survival rate (OS) and cancer-specific survival rate and End Results (SEER) registry (CSS) months (m) were evaluated with corresponding 95% confidence intervals (95% CIs). Propensity score matching (PSM) was performed to adjust for potential baseline confounding of all comparison groups. Results: In general, receiving both primary and metastatic tumor resection (PMTR) remarkably improved OS and CSS compared with only primary tumor resection (PTR) after PS matching (PSM) (P < 0.05), with a significantly improved OS (HR = 0.74, 95%CI = 0.69-0.80) and CSS (HR = 0.71, 95%CI = 0.66-0.76) in all stage M1 colon patients. The stratification analysis indicated a significant difference between OS and CSS in M1a and M1b stages. After PSM, PMTR was found to be associated with remarkably improved OS and CSS for patients with liver metastases but not associated with OS and CSS of patients with lung metastases in both M1a and M1b stage. Conclusions: The results from this large SEER cohort supported PMTR might improve the survival of colon patients with liver metastases on the basis of chemotherapy.

Effects of straw mulching and nitrogen application rates on crop yields, fertilizer use efficiency, and greenhouse gas emissions of summer maize.

Although straw mulching and nitrogen applications are extensively practiced in the agriculture sector, large uncertainties remain about their impacts on crop yields and especially the environment. The responses of summer maize yields, fertilizer use efficiency, and greenhouse gas (GHG) emissions including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in the North China Plain (NCP) to two straw management practices (S0: no straw and S1: straw mulching) and two nitrogen application rates (N1: 180 and N2: 210 kg N ha-1) were investigated in field tests in 2018, 2019, and 2020. The highest yields and partial factor productivity (PFP) were obtained by S1N1, followed by S1N2, S0N1, and S0N2. S1N2 had the highest CO2 emissions and greatest CH4 uptake, S0N1 had the lowest CO2 emissions, and S0N2 had the smallest CH4 uptake. The highest and lowest N2O emissions were found in S0N1 and S1N1, respectively. The S1N2 treatment, an extensively applied practice, had the greatest global warming potential (GWP), which was 70.3 % larger than S1N1 and two times more than S0N1 and S0N2. The largest GHG emission intensity (GHGI) of 19.4 was found in the S1N2 treatment, while the other three treatments, S0N1, S0N2, and S1N1, had a GHGI of 10.1, 10.7, and 10.7, respectively according to three tested results. In conclusion, S1N1 treatment achieved a better trade-off between crop yields and GHG emissions of summer maize in NCP.

Effects of no-tillage on greenhouse gas emissions in maize fields in a semi-humid temperate climate region.

Agricultural tillage practices have a significant impact on the generation and consumption of greenhouse gases (GHGs), the primary causes of global warming. Two tillage systems, conventional tillage (CT) and no-tillage (NT), were compared to evaluate their effects on GHG emissions in this study. Averaged from 2018 to 2020, significant decreases of CO2 and N2O emissions by 7.4% and 51.1% were observed in NT as compared to those of CT. NT was also found to inhibit the soil CH4 uptake. In this study, soil was a source of CO2 and N2O but a sink for CH4. The effect of soil temperature on the fluxes of CO2 was more pronounced than that of soil moisture. However, soil temperature and soil moisture had a weak correlation with CH4 and N2O flux variations. As compared to CT, NT did not affect maize yields but significantly reduced global warming potential (GWP) by 8.07%. For yield-scaled GWP, no significant difference was observed in NT (9.63) and CT (10.71). Taken together, NT was an environment-friendly tillage practice to mitigate GHG emissions in the soil under the tested conditions.

Virtual water transfers in Africa: Assessing topical condition of water scarcity, water savings, and policy implications.

Africa is facing an increasing challenge with respect to water scarcity (WS), which is driven by climate change, population growth, and socioeconomic growth combined with inadequate water resources management. In particular, there is significant concern of virtual water (VW) trade, which plays the key role in water resource management and food security sustainability. Using bilateral trade data, this study consistently evaluated the change and balanced trade of major grains, the VW flows, WS status, water dependency (WD), water self-sufficiency (WSS), and water savings/losses within5 African sub-regions and their partners from 2000 to 2020. The ratio of water use to water availability was used to estimate the WS. The WD was quantified by the ratio of the net VW import to the regional water appropriation and the regional water savings/losses were also quantified by multiplying the inter-regional trade by the virtual water content of the imported/exported grains. The overall average trade deficit of African regions was found to increase to -1364.22 × 106 tons and Africa imported 41,359.07 Bm3 of VW from grain products. Green water contributed 79.33% of the total VWI. The WS values for East African countries were >100, indicating overexploitation. Besides, the overall WD in Africa was 465.5% for the studied period. The trade of main grains between Africa and the rest of the planet corresponded to a global water loss of 2820.7 Bm3·yr-1. However, the inter-continental cereal VW trade pattern and high trend will continue in the future. In view of the rising tension of WS, some African countries need to revise international crop trade and water resources conservation policies to promote a more balanced ecosystem. This study exemplifies that decision makers would consider VW flows and water savings/losses for enhancing water use efficiency and fair trading, thus increasing food production in Africa.

Neoadjuvant and Adjuvant Treatments Compared to Concurrent Chemoradiotherapy for Patients With Locally Advanced Cervical Cancer: A Bayesian Network Meta-Analysis.

Aim: This study aimed to identify the most effective treatment mode for locally advanced cervical cancer (LACC) by adopting a network meta-analysis (NMA). Methods: Randomized controlled trials about treatments were retrieved from PubMed, Medline and Embase. Odds ratios (OR) of overall survival (OS) and progression-free survival (PFS) were calculated by synthesizing direct and indirect evidence to rank the efficacy of nine treatments. Consistency was assessed by node-splitting method. Begg's test was performed to evaluate publication bias. The surface under cumulative ranking curve (SUCRA) was also used in this NMA. Results: A total of 24 eligible randomized controlled trials with 6,636 patients were included in our NMA. These trials compared a total of nine different regimens: radiotherapy (RT) alone, surgery, RT plus adjuvant chemotherapy (CT), concurrent chemoradiotherapy (CCRT), neoadjuvant CT plus CCRT, CCRT plus adjuvant CT, neoadjuvant CT, RT, CCRT plus surgery. Among those therapeutic modalities, we found that the two interventions with the highest SUCRA for OS and PFS were CCRT and CCRT plus adjuvant CT, respectively. ORs and 95% confidence interval (CI) for the two best strategies were CCRT versus CCRT plus adjuvant CT (OR, 0.84; 95% CI, 0.53-1.31) for OS, CCRT plus adjuvant CT versus CCRT (OR, 0.60; 95% CI, 0.38-0.96) for PFS. Conclusions: This NMA supported that CCRT and CCRT plus adjuvant CT are likely to be the most optimal treatments in terms of both OS and PFS for LACC. Future studies should focus on comparing CCRT and CCRT plus adjuvant CT in the treatment of LACC. Systematic Review Registration: PROSPERO, CRD42019147920.

Evaluation of no-tillage impacts on soil respiration by 13C-isotopic signature in North China Plain.

It is a challenge to characterize soil respiration of crop residue return systems in the North China Plain (NCP) under no-tillage (NT) and conventional tillage (CT) practices. In this study, we addressed the "hot spot" research challenge of impacts of tillage practices on soil carbon storage and soil CO2 emissions in the NCP by 13C-isotopic signature. A short-term (2018-2020) field experiment was conducted with two tillage practices: NT and CT. The results showed that in the tested area, NT had advantages of lower CO2 emissions compared to CT with average reduced CO2 emissions by 10.82%-19.14%. The results of this study suggested that the NT facilitated enhanced soil carbon storage by 2.80%, which was evidenced by the δ13C data. Based on the path analysis model, the main line of soil respiration reduced by NT was attributed to the increased of soil microbial carbon and nitrogen as well as soil moisture in NT, which further increased δ13C and eventually inhibited soil respiration. Overall, adopting NT in NCP is an effective means to improve soil carbon pool and decrease soil CO2 emissions in agriculture practices.

Efficiency and driving force assessment of an integrated urban water use and wastewater treatment system: Evidence from spatial panel data of the urban agglomeration on the middle reaches of the Yangtze River.

With the rapid development of urban agglomerations, urban water use and wastewater environments have gradually constrained sustainable development and caused increasing concern. In this paper, we selected the urban agglomeration on the middle reaches of the Yangtze River (UAMRYZ) as a typical area. We proposed an integrated urban water use and wastewater treatment (UWUWT) system and its urban water use (UWU) subsystem and urban wastewater treatment (UWT) subsystem. Moreover, an integrated two-stage slacks-based measure (SBM) data envelopment analysis (DEA) model was used to evaluate the efficiency of the UWUWT system and its subsystem during 2010 to 2017. Additionally, the multiscale geographically weighted regression (MGWR) model was adopted to analyze the influence mechanism of each factor on the defined system. The results indicated that the tendency of UWU efficiency and UWUWT efficiency were similar and mainly showed the same trend with an 'N' shape in a time-dependent manner for the UAMRYZ and provinces, respectively. Furthermore, the UWU efficiency and UWUWT efficiency of each city showed strong spatiotemporal heterogeneity. The UWT efficiency of the UAMRYZ and its representative cities was stable in the region and always had a higher value. With continuous economic development and increased interregional foreign trade, the UWU subsystem efficiency and the UWUWT system efficiency had a significant increase for cities along the entire river in the Yangtze Basin. The regional differences of the overall UWU efficiency, UWT efficiency and UWUWT efficiency gradually decreased and the efficiency has gradually improved from 2010 to 2017. Attribution analysis showed that the secondary industry was the main constraining factor, while the water resource was the most acceleration factor for the UWUWT system in most areas and the UWT subsystem for all cities. Our study evaluated the specific insufficiencies of the defined system and supported regulatory policies.

Influence of the shallow groundwater table on the groundwater N2O and direct N2O emissions in summer maize field in the North China Plain.

Agriculture is an important N2O emissions source. Water cycle and nitrogen cycles have important effects on N2O in farmland ecosystems. The changes in the groundwater table can lead to changes in farmland the water and nitrogen cycle processes. However, how this such changes will affect N2O emissions from farmland remains unclear. In this study, a two-year volume lysimeter experiment (2019-2020), including four controlled groundwater tables (i.e., 40, 70, 110, and 150 cm), was performed to monitor the variations in the NO3- and N2O concentrations in shallow groundwater as well as the direct N2O emissions due to surface soil and groundwater evaporation. Our results showed that N2O emissions during fertilization accounted for 80%-90% of the total N2O emissions throughout the maize growing period. Direct N2O emissions increase with the increase in the groundwater table. The total N2O emissions in 2020 were 96.44, 9.75, 6.46, and 6.22 kg ha-1 y-1 at a groundwater table of 40, 70, 110, and 150 cm, respectively. The high water-filled pore space (WFPS) value resulting from the elevated groundwater table increased the groundwater-atmosphere connectivity, leading to significantly increased N2O emissions after fertilization. Increased precipitation (454.90 mm in 2020 vs. 180.30 mm in 2019) accelerated the hydrological processes in agroecology, reducing the retention time of N2O (6 weeks in 2020 vs. 7.5 weeks in 2019) and NO3- (6.75 weeks in 2020 vs. 7.25 weeks in 2019) in shallow groundwater. Studying the influence of shallow groundwater tables on direct N2O emissions will provide insights into the interaction between the water and nitrogen cycles in agroecosystems. The results of this study suggest that direct N2O emissions can be effectively reduced by controlling the groundwater table in agricultural fields in the North China Plain.

Agricultural impacts drive longitudinal variations of riverine water quality of the Aral Sea basin (Amu Darya and Syr Darya Rivers), Central Asia.

River ecosystems are under increasing stress in the background of global change and ever-growing anthropogenic impacts in Central Asia. However, available water quality data in this region are insufficient for a reliable assessment of the current status, which come as no surprise that the limited knowledge of regulating processes for further prediction of solute variations hinders the development of sustainable management strategies. Here, we analyzed a dataset of various water quality variables from two sampling campaigns in 2019 in the catchments of two major rivers in Central Asia-the Amu Darya and Syr Darya Rivers. Our results suggested high spatial heterogeneity of salinity and major ion components along the longitudinal directions in both river catchments, pointing to an increasing influence of human activities toward downstream areas. We linked the modeling outputs from the global nutrient model (IMAGE-GNM) to riverine nutrients to elucidate the effect of different natural and anthropogenic sources in dictating the longitudinal variations of the riverine nutrient concentrations (N and P). Diffuse nutrient loadings dominated the export flux into the rivers, whereas leaching and surface runoff constituted the major fractions for N and P, respectively. Discharge of agricultural irrigation water into the rivers was the major cause of the increases in nutrients and salinity. Given that the conditions in Central Asia are highly susceptible to climate change, our findings call for more efforts to establish holistic management of water quality.

Influence of no-tillage and precipitation pulse on continuous soil respiration of summer maize affected by soil water in the North China Plain.

Soil respiration (RS) from cropland in response to tillage practices contribute to global climate change. We quantified the effect of no-tillage (NT) and conventional tillage (CT) on RS and precipitation in the North China Plain (NCP). An in-situ automatic sampling and measurement method was applied during the maize (Zea mays L.) growth stages in 2018 and 2019. The continuous daily RS, soil water content and temperature were monitored during all the maize growth stages, whereas maize grain yield, aboveground biomass, and soil microbial biomass were measured after harvest. The mean RS across tillage practices on bright days was higher in 2018 (16.69 g CO2 m-2 d-1) than that in 2019 (12.99 g CO2 m-2 d-1). Compared with CT, NT increased RS on bright days by 31.44% in 2018 and 15.60% in 2019. However, mean RS on rain-affected days across tillage practices was lower in 2018 than that in 2019. NT increased mean RS after precipitation in 2018 (p < 0.05). The contribution of RS after precipitation to cumulative RS (across tillage practices) was higher in 2019 (51.90%) than that in 2018 (41.18%). Mean soil water content and temperature were higher in 2018 than that in 2019 (p < 0.05). NT increased soil water content on bright days in 2019. Furthermore, soil water content was more important in regulating RS in 2018, while soil temperature was more critical after precipitation in 2019. Crop productivity was lower in 2019 than in 2018 (p < 0.05). However, neither crop productivity nor soil microbial biomass varied with tillage practices (p > 0.05). Overall, influence of tillage practices and precipitation on RS were different according to soil water content. Therefore, it is necessary to decrease excessive irrigation to reduce RS in dry years and to conduct continuous observations on RS after precipitation in the NCP.

The stage-specific roles of radiotherapy and chemotherapy in nodular lymphocyte predominant Hodgkin lymphoma patients: a propensity score-matched analysis of the SEER database.

BACKGROUND: The stage-specific roles of radiotherapy (RT) alone, chemotherapy alone, and combined RT and chemotherapy (CRT) for patients with nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) have not been adequately evaluated. METHODS: We analyzed patients with all stages of NLPHL enrolled in the Surveillance, Epidemiology, and End Results (SEER) registry from January 2000 to December 2015. Propensity score (PS) analysis with 1:1 matching (PSM) was performed to ensure the well-balanced characteristics of the comparison groups. Kaplan-Meier and Cox proportional-hazards models were used to evaluate the overall survival (OS), cancer-specific survival (CSS), hazard ratios (HRs), and corresponding 95% confidence intervals (95% CI). Restricted mean survival times (RMST) were also used for the survival analyses. RESULTS: For early-stage patients, CRT was associated with the best survival, the mean OS was significantly improved by approximately 20 months (20 m), and the risk of death was reduced by more than 80%, both before and after PSM (p < 0.05). For advanced-stage patients, none of RT alone, chemotherapy alone, or CRT had a significant effect on survival. Chemotherapy alone and CRT might be more beneficial for long-term survival (RMST120 m : neither RT nor chemotherapy vs. chemotherapy alone vs. CRT = 104 m vs. 111 m vs. 108 m). Subgroup analysis of patients with early-stage NLPHL showed that CRT was associated with better survival of elderly patients (improved OS = 43.8 m, HR = 0.14, p < 0.05). However, the survival benefits of treatments for young patients were not statistically significant. The efficacy of RT was significantly different between the age groups (pfor interaction  = 0.020). CONCLUSIONS: These results from SEER data suggest that CRT may be considered for early-stage NLPHL, especially for elderly patients. Further studies are needed to identify effective treatments in patients with advanced-stage NLPHL.

Radiotherapy for patients with stage IV classical Hodgkin lymphoma: a propensity-matched analysis of the surveillance, epidemiology, and end results database.

Background The survival advantage of radiotherapy for patients with stage IV classic Hodgkin lymphoma (HL) has not been adequately evaluated. Methods We analyzed patients with stage IV HL enrolled from the Surveillance, Epidemiology, and End Results (SEER) registry from January 2000 to December 2012. Propensity score (PS) analysis with 1:2 matching was performed to ensure well-balanced characteristics of the comparison groups. Kaplan-Meier and Cox proportional hazardous model were used to evaluate the overall survival (OS), cancer-specific survival (CSS), the hazards ratio (HR) and corresponding 95% confidence intervals (95% CI). Results Overall, for all patients with stage IV HL, receiving radiotherapy was associated with both significantly improved OS and CSS. Radiotherapy to any lesions could independently improve the OS and CSS by 30% to 36% in the multivariate analyses before and after PS matching (PSM), with the best improvement of 33% to 40% observed for patients with nodular sclerosis (P < 0.05) among all HL pathological types. In particular, radiotherapy, most likely to the residual site, was more pronouncedly associated with the improvement in survival for patients with stage IV HL who were young (age<45, P < .05) or without B symptoms (PInteraction for OS = 0.099, PInteraction for CSS = 0.255). For those patients without B symptoms, after PSM, the OS was improved by 65% (P = .021). Conclusions The large SEER results support that radiotherapy is associated with better survival of patients with stage IV HL.

Comparison of Treatment Modalities for Locally Advanced Gastric Cancer: A Propensity Score Matching Analysis.

Background: A consensus regarding optimum treatment strategies for locally advanced gastric cancer (LAGC) has not yet been reached. We aimed to evaluate the efficacy of various treatment modalities for LAGC and provided clinicians salvage options under real-world situation. Methods: Medical charts of patients with LAGC who underwent radical resection plus adjuvant chemotherapy or chemoradiotherapy from July 2003 to December 2014 were included. Validation cohort were selected from SEER database between 2004 and 2014. Kaplan-Meier and Cox proportional hazardous models were used to evaluate the overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Propensity score matching (PSM) was used to adjust for potential baseline confounding. Results: A total of 350 patients were included and divided into D1 dissection plus chemotherapy group (D1CT, n = 74), D1 dissection plus adjuvant chemoradiotherapy group (D1CRT, n = 69), D2 dissection plus adjuvant chemotherapy group (D2CT, n = 134), and D2 dissection plus adjuvant chemoradiotherapy group (D2CRT, n = 73). PSM identified 50 patients in each group. After PSM, better DFS (P for D2CRT vs. D1CT, D1CRT, and D2CT was 0.001, 0.006, and 0.001, respectively) and OS (P for D2CRT vs. D1CT, D1CRT, and D2CT was 0.001, 0.011, and 0.022, respectively) were found for the D2CRT group (mean, OS = 110.7months, DFS = 95.2 months) than the other groups. Similar findings were further validated in the Surveillance, Epidemiology, and End Results database (SEER) cohort. In addition, patients in the D1CRT group achieved similar survival outcomes to those in the D2CT group (mean OS, 72.8 vs. 59.1 months, P = 0.86; mean DFS, 54.4 vs. 34.1 months, P = 0.460). Conclusions: The results of the study indicated the better role for D2CRT in treating the LAGC, meanwhile, the patients treated with D1CRT might achieve similar survival as that of D2CT patients.

Spatial Distribution and Health Risk Assessment of Dissolved Trace Elements in Groundwater in southern China.

To understand the groundwater environmental quality and the impact of trace elements in the construction of urban agglomeration in China, this study collected 58 groundwater samples from the core area of the Chang-Zhu-Tan urban agglomeration (Changsha, Zhuzhou, Xiangtan) and quantitatively analyzed the content of 13 dissolved trace element and their spatial distribution characteristics. The health risk assessment model was further used to evaluate the human health risk caused by trace element pollution in groundwater. It was observed that Ba had the highest average concentration (0.28 mg·L-1), whereas Cd had the lowest (2.1 × 10-5 mg·L-1). Compared with China's groundwater environmental quality standard, the exceeding rates of Se, Mn, Zn, and Ni concentrations were 37.93%, 17.24%, 1.72% and 1.72%, respectively. Ba, Cd, Co, Cr, Cu, Fe, Mo, and Pb did not exceed the corresponding standards. The 13 trace elements were distributed in a scattered pattern in space and the trace elements in both banks of the Xiang River, Zhuzhou, Weishui River and surrounding areas were relatively high. Health risk assessments showed that the carcinogenic risk values of Cd, Cr, and Pb and the health risk values of 10 non-carcinogenic elements were less than the corresponding maximum acceptable risk level. The health risks associated with non-carcinogenic substances through ingestion were higher than those associated with dermal absorption. Among the non-carcinogenic substances, Ba and Mn posed the greatest health risks. With respect to drinking water exposure, Cr had the highest carcinogenic risk, followed by Pb. Furthermore, Cd had the lowest carcinogenic risk. This study recommended that continuous monitoring of Ba, Mn, and Cr in groundwater should be practiced by assessing the risk of these elements in the Chang-Zhu-Tan urban agglomeration.