Speciation of Main Nutrients (N/P/K) in Hydrochars Produced from the Hydrothermal Carbonization of Swine Manure under Different Reaction Temperatures

Hydrothermal carbonization (HTC) has been proved to be a promising technology for swine manure (SM) treatment. Currently, there is a lack of systematic understanding of the transformation characteristics of nutrient speciation in the HTC of SM. In this study, the speciation of the main nutrients (N/P/K) in SM-derived hydrochar produced at different reaction temperatures (200–280 °C) was investigated. The recovery of P (61.0–67.1%) in hydrochars was significantly higher than that of N (23.0–39.8%) and K (25.5–30.0%), and the increase in reaction temperature promoted the recovery of P and reduced the recovery of N. After the HTC treatment, the percentage of soluble/available P was reduced from 61.6% in raw SM to 4.0–23.9% in hydrochars, while that of moderately labile/slow-release P was improved from 29.2% in raw SM feedstock to 65.5–82.7%. An obvious reduction was also found in the amounts of available N (from 51.3% in raw SM feedstock to 33.0–40.5% in hydrochars). The percentages of slow-release N and residual N in hydrochars produced at 240 °C reached the maximum and minimum values (46.4% and 18.9%), respectively. A total of 49.5–58.3% of K retained in hydrochars was residual (invalid) potassium. From the perspective of the mobility and availability of N, P and K only, it was suggested that the HTC of SM should be carried out at 220–240 °C. Compared with the original SM, it is safer and more effective to use the SM-derived hydrochar as an organic fertilizer.

Impacts of green manure on crop yield, nitrogen leaching and nitrous oxide emissions in sandy and clay soil lysimeters

We compared wheat yield, losses of nitrogen (N) in leaching, and gaseous losses as nitrous oxide (N2O) in silt and sand soil lysimeters. The studied cultivation systems were based on mineral fertilizer or mineral fertilizer together with clover green manure mulched at three different time points (August, October or May) before sowing of the main crop (either winter or spring wheat). Replacing 50–60% of mineral fertilizer N with green manure from a mixture of three clover species did not compromise the crop yield of winter or spring wheat. The results suggest that mulching of the green manure in the spring succeeding its sowing is the most beneficial practice with respect to environmental impacts. Total N leaching was higher from sandy soil than from silt loam whereas emissions of N2O were higher from the silt soil. Residual N from the clover biomass did not lead to an increase in leaching losses of N during the growing season or one year from the harvest. However, the residual N can be a source of high N2O emissions during the winter period in boreal climatic conditions.

Reassessment of the Contribution of Belowground N from Soybean after Testing Different 15N Leaf-Labelling Strategies

Purpose: Soybean is the most important grain crop in Brazil with a mean N accumulation of over 250 kg N ha-1, principally from biological N2 fixation. The residual N benefit depends heavily on the quantity of the belowground N at harvest, much which cannot be directly recovered in roots. The purpose of this study was to investigate different aspects of the 15N leaf-labelling technique to quantify non-recoverable root N (NRRN) derived from senescent roots and nodules (rhizodeposits). Methods: Soybean plants were grown in pots of soil and at 27 days after planting (vegetative stage V4) cut or whole leaves were exposed to highly enriched 15N-labelled urea or glutamine. Seven sequential harvests of the plants and soil were taken until the final grain harvest at 70 days after labelling.Results: After only 48 h, the plants labelled with 15N urea transferred approximately 5% to the soil, while only 1% was found in the roots. Leakage of 15N label was even more pronounced when the leaves were labelled with 15N glutamine. After this initial leakage, the excess 15N deposited in the soil only increased by a further 2.6% of applied label, which suggested that only part of this N represented senescence of roots or nodules.Conclusions At the final harvest, N in roots separated from the soil amounted to 6.4% of total plant N. Discounting the early rapid deposition of 15N-enriched N to the soil, our calculations indicated that at final harvest the total NRRN was 2.8% of total plant N.

Nitrogen Fate and Efficiency of Fertilizer Application under a Rapeseed–Wheat–Rice Rotation System in Southwest China

To evaluate the efficient use of nitrogen (N) for rice in a rapeseed–wheat–rice rotation system, a pot experiment was conducted. The results indicated that in the conventional 15N-labeled (Nc) and reduced 15N-labeled (Nr) urea applications, absorbed N and soil residual N was higher in rapeseed than in wheat. In the rice season, the higher accumulation of 15N was achieved with an Nr application rate during the rapeseed season and an N fertilizer management model (40% as basal fertilizer, 40% as tillering fertilizer, and 20% as panicle fertilizer) during the rice season (PrNrM3). A high 15N accumulation was also achieved under the Nc application rate during the wheat season and the N fertilizer management model during the rice season (PwNcM3). The accumulation of 15N in PrNrM3 and PwNcM3 accounted for 21.35% and 36.72% of the residual N under the Nr application rate in the rapeseed season and the Nc application rate in the wheat season, respectively. Compared with the Nc application rate in the rapeseed season and M3 N management in the rice season (PrNcM3), the N agronomy efficiency (NAE) and the N partial factor efficiency (NPFP) of rice were increased by 23.85% and 1.59%, respectively, in PrNrM3. The annual crop yield was 3.95% lower in PrNrM3, which was not significant. PrNrM3 was a stable yield, N-saving application rate for rapeseed-rice rotation systems in southern China.

Colangiopancreatografía retrógrada endoscópica en una institución de referencia en cáncer.

Introducción: la endoscopia es una de las herramientas necesarias para el manejo de las enfermedades biliares y pancreáticas. La colangiopancreatografía retrógrada endoscópica (CPRE) es uno de los procedimientos técnicamente más demandantes y de mayor riesgo de complicaciones realizados en el tratamiento de los desórdenes hepatopancreatobiliares. Objetivo: caracterizar los resultados clínicos de los pacientes llevados a CPRE en un centro de pacientes con cáncer exclusivamente. Métodos: estudio de serie de casos observacional, retrospectivo, descriptivo con base en datos clínicos de pacientes llevados a CPRE en una población diagnosticada con cáncer de distintos orígenes primarios y en diferentes estadios de enfermedad desde enero de 2010 hasta enero de 2017. Resultados: se analizaron 255 procedimientos en los que predominó el sexo femenino con 140 casos (54,9 %), el promedio de edad fue 62,9 años (desviación estándar [DE]: 12,9 años). Todos los procedimientos se hicieron con intención terapéutica. La indicación más frecuente fue cáncer de páncreas (n = 47; 18,43 %), compresión extrínseca de la vía biliar (n = 42; 16,47 %), disfunción de prótesis (n = 36; 14,12%), colecistocoledocolitiasis (n = 32; 12,55 %), otras causas (n = 32; 12,55 %), cáncer de vesícula (n = 24; 9,41 %), colangiocarcinoma extrahepático (n = 21; 8,24 %), coledocolitiasis recidivante (n = 9; 3,53%), coledocolitiasis residual (n = 6; 2,35 %) y tumor de Klatskin (n = 6; 2,35 %). La canalización exitosa se presentó en 222 casos (87,06 %). Durante el procedimiento, 10 pacientes presentaron complicaciones (4,3 %), de las cuales la pancreatitis y las perforaciones fueron las más frecuentes (n = 3; 1,18 %), seguidas por sangrado, colangitis (n = 2; 0,78 %) y dolor post-CPRE 1 (0,39 %). Conclusiones: en la población evaluada, la causa predominante para realizar el procedimiento está relacionada con cáncer y la frecuencia tanto de canalización exitosa como de complicaciones es similar a la de los reportes en las poblaciones generales.

Performance of a Toxo IgM prototype assay for the diagnosis of maternal and congenital Toxoplasma infections

BackgroundTesting for anti-Toxoplasma immunoglobulin (Ig)M is of main importance in the context of pregnancy to promptly alert to an acute maternal infection prior to the detection of IgG and to identify infected newborns. Their absence helps exclude a recent maternal infection in the presence of IgG.MethodsThe performance of a Toxo IgM immunocapture prototype assay (bioMérieux, France) was compared with that of the VIDAS® Toxo IgM and the ARCHITECT® Toxo IgM (Abbott, Germany) assays at Grenoble and Lyon (France). A total of 1446 sera were sampled from (i) 1054 pregnant women found by routine workup to have no infection (n = 843), an acute infection (<4 months) (n = 28) or a chronic infection (>4 months) with residual (n = 120) or no IgM (n = 62); (ii) 50 three-serum panels sampled immediately after a maternal seroconversion; (iii) 242 samples taken in 41 children with a congenital toxoplasmosis (n = 122) and in 40 uninfected children (n = 120).ResultsIn pregnant women, the overall agreement with the VIDAS® assay was 99.23% (CI: 99.16–99.27) and that with the ARCHITECT® assay was 99.14% (CI: 99.07–99.17). Sensitivity of the Toxo IgM prototype assay was 100% (CI: 87.66–100.00) and specificity was 99.64% (98.96–99.93). In acute maternal infections, IgM assays were detected as early with the prototype as with the other two. In the congenitally infected children, IgM were detected on their first sample in 25/40 with the prototype vs. 23/40 with the VIDAS® test. No uninfected child had positive IgM. ConclusionThe prototype performed comparably to the ARCHITECT® and VIDAS® Toxo IgM assays for the diagnosis of maternal and congenital toxoplasmosis.

Heterogeneity in Decomposition Rates and Nutrient Release in Fine-Root Architecture of Pinus massoniana in the Three Gorges Reservoir Area

Fine-root decomposition contributes a substantial amount of nitrogen that sustains both plant productivity and soil metabolism, given the high turnover rates and short root life spans of fine roots. Fine-root decomposition and soil carbon and nitrogen cycling were investigated in a 1-year field litterbag study on lower-order roots (1–2 and 3–4) of Pinus massoniana to understand the mechanisms of heterogeneity in decomposition rates and further provide a scientific basis for short-time research on fine-root decomposition and nutrient cycling. Lower-order roots had slower decay rates compared with higher-order roots (5–6). A significantly negative correlation was observed between the decay constant mass remaining and initial N concentrations as well as acid unhydrolyzable residues. Results also showed that in lower-order roots (orders 1–2 and 3–4) with a lower C:N ratio, root residual N was released and then immobilized, whereas in higher-order roots (order 5–6) with a higher C:N ratio, root residual N was immobilized and then released in the initial stage. In the later stage, N immobilization occurred in lower-order roots and N release in higher-order roots, with the C:N ratio gradually decreasing to about 40 in three branching-order classes and then increasing. Our results suggest that lower-order roots decompose more slowly than higher-order roots, which may result from the combined effects of high initial N concentration and poor C quality in lower-order roots. During the decomposition of P. massoniana, N release or N immobilization occurred at the critical C:N ratio.

Productive Impact of Residual Nutrients (N and P) in Maize and Soybean Rotation

Agricultural intensification has resulted in severe soil nutrient depletion in Africa. Alternative agricultural practices have been promoted to restore and sustain soil fertility. Use of mineral fertilizer alongside different cropping systems has been particularly promising. This study was conducted in the Guinea savannah zone of Ghana during the 2015 and 2016 cropping season (July to November) to assess the performance of soybean and maize in a rotation system. In season one, using randomized complete block design the treatments were, soybean (without treatment), inoculated soybean, soybean with phosphorus application, inoculated soybean with phosphorus application and maize. During the second season, the first season experimental plots served as main-plots and divided into four sub-plots on which maize planted and treated with four nitrogen rates in a split plot design. The results show that soybean production leads to significant increase in residual soil nitrogen content of about 16kg/ha to 55kg/ha, which is about 28 folds higher than that observed in maize fields. The level of Residual N was enhanced with inoculation. Phosphorus application during the first season of maize cultivation led to increases in residual P levels, which had a positive impact on yield of soybean in the second season. Grain yield of maize that followed soybean in a rotation system performed better than maize that followed maize at various fertilizer rates. This shows that, the residual N and P helps maize and soybean respectively in a rotation system which makes it highly economical.