Levels of Serum IGF-1, HCY, and Plasma BNP in Patients with Chronic Congestive Heart Failure and Their Relationship with Cardiac Function and Short-Term Prognosis.

Objective: To investigate the levels of serum insulin like growth factor-1 (IGF-1), homocysteine (HCY), and plasma brain natriuretic peptide (BNP) in patients with chronic congestive heart failure (CCHF) and their relationship with cardiac function and short-term prognosis. Methods: A total of 95 patients with CCHF admitted to our hospital from October 2017 to December 2018 were selected as the observation group. Patients conform to grade II∼IV of the New York Heart Association (NYHA) heart function class. At the same time, the people with normal physical examination results were selected as a control group. Serum IGF-1, HCY, and plasma BNP levels were detected in the two groups, and left ventricular end-diastolic diameter (LVDd) and left ventricular ejection fraction (LVEF) were detected in the observation group. According to the follow-up results, the observation group was divided into the subgroup with good prognosis and the subgroup with poor prognosis. The relationship between the levels of serum IGF-1, HCY, and plasma BNP among cardiac function and short-term prognosis were analyzed. Results: The serum IGF-1 level of the observation group was lower than that of the control group, and the serum HCY and plasma BNP levels were higher than those of the control group (P < 0.05). Serum IGF-1 level in grade III of NYHA was lower than that in grade II, and serum HCY and plasma BNP levels were higher than those in grade II. Serum IGF-1 level in grade IV was lower than that in grade II and grade III, and serum HCY and plasma BNP levels were higher than those in grade II and grade III (P < 0.05). Serum IGF-1 level was negatively correlated with LVDd and positively correlated with LVEF. Serum HCY and plasma BNP levels were positively correlated with LVDd and negatively correlated with LVEF (P < 0.05). There were 42 patients with poor prognoses (44.21%). Serum IGF-1 levels of patients with poor prognosis were lower than those with good prognosis, and serum HCY and plasma BNP levels were higher than those with good prognosis (P < 0.05). Conclusion: The serum IGF-1 level in patients with CCHF decreased, and serum HCY and plasma BNP levels increased. Serum IGF-1, HCY, and plasma BNP were correlated with cardiac function and have some clinical value for short-term prognosis.

Silicon as a potential limiting factor for phosphorus availability in paddy soils.

Rice cultivation requires high amounts of phosphorus (P). However, significant amounts of P fertilizer additions may be retained by iron (Fe) oxides and are thus unavailable for plants. At the same time, rice cultivation has a high demand for silicic acid (Si), reducing Si availability after short duration of rice cultivation. By studying a paddy chronosequence with rice cultivation up to 2000 years, we show that Si limitation, observed as early as a few decades of rice cultivation, is limiting P availability along the paddy soils chronosequence. Using near edge X-ray absorption fine structure spectroscopy (NEXAFS) in a scanning transmission (soft) X-ray microscope (STXM) we show release of available P was linked to a Si-induced change in speciation of Fe-phases in soil particles and competition of Si with P for binding sites. Hence, low Si availability is limiting P availability in paddy soils. We propose that proper management of Si availability is a promising tool to improve the P supply of paddy plants.

Effect of dietary vitamins in oral bioaccessibility of lead in contaminated soils based on the physiologically based extraction test.

To determine the effect of vitamin supplements on the oral bioaccessibility of Pb in soils, Pb bioaccessibility was measured in the presence of 9 vitamins by a physiologically based extraction test. Gastric Pb bioaccessibility (G-BA, 2.6-83.3%) was found to be mostly reduced (1.1-3.1 fold) in the presence of B vitamins, specifically vitamins B1, B6, and B9. In contrast, a significant increase in Pb G-BA was observed with vitamin C and E involved. In the small intestinal phases, Pb bioaccessibility (I-BA) ranged from 0.1% to 16.0%, being 5-50 fold lower than the corresponding G-BA values. Vitamin C supplementation showed a 7-fold increase in Pb I-BA, with a similar increase presented in approximately 30% of samples treated to vitamin B involvement. Lead liberation in gastrointestinal digests was associated with the dissolution of Fe and Mn regulated by vitamins. In conclusion, the addition of B vitamins resulted in the reduction of gastric Pb bioaccessibility, but the bioaccessibility value increased in participation of vitamin C and E. Elevated intestinal bioaccessibility was found especially for vitamin C. This should contribute to more accurate assessment of health risks from contaminated soils. Nutritional management aimed at preventing Pb-induced toxicity can benefit from knowledge of vitamin influence on soil Pb bioaccessibility.

Sulfur controlled cadmium dissolution in pore water of cadmium-contaminated soil as affected by DOC under waterlogging.

Cadmium (Cd) precipitation and dissolution in pore water is associated with dissolved organic carbon (DOC)-induced reduction-oxidation of sulfur (S) under waterlogging and is vital for controlling the bioavailability in paddy soil. A 120-day soil incubation experiment, including application of sulfur (S, 30 mg kg-1) and wheat straw (W, 1.0%) alone or in combination (W + S) into Cd-contaminated paddy soil under waterlogging, was conducted to investigate the dynamic of dissolved Cd and its relationship with DOC, S2-, Fe2+, pH, Eh and pe + pH in soil pore water. The results showed that the lowest dissolved Cd concentration was observed in the W + S-treated soil pore water among all treatments when the soil Eh remained at lower values during the period of 15-60 days of incubation, which could be attributed to CdS precipitation and/or co-precipitation of Cd absorbed by FeS2 because of the reduction in sulfur. The application of S resulted in a Cd rebound in the pore water irrespective of W addition when the Eh began to increase from its lowest values during the period of 45-75 days of incubation, and SOB genera were observed in the S added soil. This could be attributed to re-dissolution of the precipitated Cd in soils under the SOB-driven oxidation of sulfide such as CdS and FeS2. In conclusion, DOC-driven reduction-oxidation of sulfur controls Cd dissolution in the pore water of Cd-contaminated paddy soil under waterlogging conditions. Further studies are required to investigate the interaction of sulfur and SOM-induced DOC on Cd bioavailability in rice-planted paddy soils.

Phosphorus Leaching from Soil Profiles in Agricultural and Forest Lands Measured by a Cascade Extraction Method.

The risk of P leaching from topsoil based on the change-point estimated via a split-line model between Olsen P and leachable P extracted by 0.01 M CaCl has been reported. However, little information is available for the assessment of P leaching from soil profiles. In this study, samples were collected at three depth profiles (0-20 cm, topsoil; 20-40 cm, subsoil; 40-60 cm, third-layer soil) at each of 74 sites under agriculture and forest in an agroforestry area. A cascade extraction method was proposed to determine the leachable P in the subsoil, extracted by the topsoil extraction solution; a similar extracted process was followed in the third-layer soil, and in the topsoil, it was still extracted by 0.01 M CaCl. A positive linear correlation was found between the subsoil leachable P extracted by the topsoil extraction solution and the accumulated P obtained from the subsoil leached by topsoil leachates, and so on. Therefore, the cascade extraction method for determining leachable P from topsoils and underlying soils could be valuable for predicting the potential of P leaching from soil profiles. Approximately 81, 73, and 73% of the agricultural sampling sites were at or above the change-points for the soil depths of 0 to 20, 20 to 40, and 40 to 60 cm (30.4, 32.9, and 18.2 mg kg respectively); these values were higher than those for the forest site, implying a high risk of P leaching from agricultural soil profiles in the study area.

Optimization of pollutant reduction system for controlling agricultural non-point-source pollution based on grey relational analysis combined with analytic hierarchy process.

Many technologies have been developed to control agricultural non-point-source pollution (ANPSP). However, most reduce pollution from only a single source instead of considering an entire region with multiple pollution sources as a control unit. A pollutant reduction system for controlling ANPSP at a regional scale could be built by integrating technologies and the reuse of treated wastewater (TWR) and nutrients (NR) to protect the environment and achieve agricultural sustainability. The present study proposes four systematic schemes involving TWR for irrigation and NR in a region with three sources of ANPSP (crop farming, livestock and aquaculture). Subsequently, a multi-objective evaluation model is established based on the analytical hierarchy process (AHP) combined with grey relational analysis (GRA) to identify the optimal scheme considering six indices, namely, pollutant reductions (total nitrogen, TN; total phosphorous, TP; ammonium-nitrogen, NH4+-N; and chemical oxygen demand, COD) and costs (construction and operational costs). The Taihu Lake Basin suffers from some of the worst ANPSP in China, and a case study was conducted in a town with three ANPSP sources. Four systems were developed on the basis of suggested technologies and the scenarios of TWR and NR (Scenario I: no reuse, Scenario II: reuse of all livestock wastewater and manure, Scenario III: reuse of some aquaculture wastewater, and Scenario IV: reuse of all livestock wastewater and manure and some aquaculture wastewater). Pollutant reductions were calculated based on removal efficiency and pollutant loads, which were estimated from the local pollutant export coefficients and agricultural information (crop farming, livestock, and aquaculture). The costs were determined on the basis of the total pollutant reductions and unit cost. The results showed that the optimal system was the Scenario IV because it had the highest grey correlation degree among the four proposed systems. The optimal system met the irrigation water demand in Xinjian. In the optimal system, the removal efficiencies of the pollutants TN, TP, NH4+-N, and COD were 84.3%, 94.2%, 89.6% and 94.0%, respectively. In addition, the implementation of NR in the optimal system reduced the use of chemical fertilizers by nearly 81.7 kg N ha-1 and 39.9 kg P ha-1. The proposed methods provide a reference for the construction of a pollutant reduction system for controlling ANPSP in a multi-source region.

Influence of Soil and Irrigation Water pH on the Availability of Phosphorus in Struvite Derived from Urine through a Greenhouse Pot Experiment.

One greenhouse pot experiment was used to investigate the availability of phosphorus in struvite derived from urine affected by soil pH (cinnamon soil, pH 7.3; paddy soil, pH 5.3) and irrigation water (pH 6.0 and 7.5) with bird rapeseed (Brassica campestris L.). The biomass of applied struvite in paddy soil was significantly greater than that of applied calcium superphosphate. However, statistically significant differences were not observed in cinnamon soil. Soil-applied struvite had a higher Olsen P compared to soil-applied calcium superphosphate irrespective of soil type. The biomass of applied struvite and irrigation with pH 6.0 water was greater compared to that with irrigation with pH 7.3 water irrespective of soil type, accompanied with significantly higher leaf chlorophyll concentration. Therefore, struvite has the potential to be an effective P fertilizer, and acidic irrigation water has greater influence on the availability of phosphorus in struvite than does acidic soil.

Risk of phosphorus leaching from phosphorus-enriched soils in the Dianchi catchment, Southwestern China.

As an important pathway for phosphorus (P) transport from soil to water body, P leaching has aroused attention. This study aimed to investigate the degree of risk and forms of P leaching from P-enriched soils. Surface soils were collected from forest land (FL) and open agricultural land (OAL) in typical P-enriched area of the Dianchi catchment, China. Based on analysis of soil P and water-soluble P using chemical methods and (31)P-NMR analysis, combined with a soil column leaching experiment, P forms and risk of P leaching were identified. CaCl2-extractable water-soluble organic P (CaCl2-Po), inorganic P (CaCl2-Pi), and total P (CaCl2-P) extracted using 0.01-M CaCl2 solution were found to be useful for predicting potential organic and inorganic P leaching, given a linear, positive correlation between CaCl2-P, CaCl2-Pi, and CaCl2-Po in soils and accumulated amounts of corresponding P forms in soil leachates. The majority of investigated FL was at or above the change points of 46, 46, and 42 mg AP kg(-1) for CaCl2-Pi, CaCl2-Po, and CaCl2-P, respectively, and thus at a risk of P leaching. Organic and inorganic P leaching was present in nearly all investigated OAL. CaCl2-Po accounted for 66.0 % of CaCl2-P in FL and 56.1 % in OAL. Signals of (31)P-NMR spectra were mainly attributable to orthophosphate, orthophosphate monoesters, and orthophosphate diesters in FL and OAL soils. It is important to consider P loss due to leaching of inorganic and organic P in P-enriched areas.

Phosphorus recovery from urine with different magnesium resources in an air-agitated reactor.

Phosphorus (P) recovery through struvite formation from urine has gained increasing attention as an approach to alleviate the potential shortage of P. The concentration of magnesium (Mg) is lower than those of ammonium and ortho-phosphate in urine, so the cost of adding Mg is a major economic constraint for P recovery. This study aims at evaluating the potential of seawater and bittern as Mg resources to recover P from urine in an air-agitated reactor. Results indicate that effects of seawater and bittern on P recovery from urine are comparable to that of magnesium chloride, with an average crystal size of around 34 µm under an Mg/P molar ratio of 1.3. The average crystal size of the struvite crystals obtained from high P concentration urine with different Mg resources showed no significant difference, whereas larger crystal size was obtained from low P concentration urine with bittern as Mg resource. Analysis of mainly rod-like crystals produced in the reactor indicates the presence of pure struvite (>98.0% by weight) with small amounts of calcium (<1.39% by weight). Bittern is recommended as a suitable Mg resource for P recovery because of its high Mg content and the convenience it offers in terms of transportation and storage.

Fate of phosphorus in diluted urine with tap water.

P loss during the fresh urine storage process is inevitable because of the presence of Ca and Mg. Dilution is one of the most important parameters influencing urine composition and subsequent P recovery. This study aimed to investigate the fate of P in urine with different dilution ratios (Vwater/Vurine, i.e., 0/100, 25/75, 50/50 and 75/25). The results indicate that the percentage of P loss increased from 43% to 76% as the dilution ratio increased from 0/100 to 75/25 because of more Ca and Mg obtained from tap water. Meanwhile, P removal efficiency through struvite precipitation decreased from 51% to 8% because of lower supersaturation ratio as a result of dilution. Struvite crystals with high purity were still obtained even under a dilution ratio of 50/50 urine solution. Batch experiments were also performed to study the influence of temperature (15-35°C) on P recovery and crystal size. For different dilution ratios of urine solutions, no significant discrepancy for the P removal efficiencies were observed at 15 and 35°C, whereas the P removal efficiencies at 25°C showed an increasing gap with those at 15 and 35°C. The largest average crystal sizes were found at 25°C, which was opposite to the trend of P removal efficiency.

Effect of hydraulic retention time and seed material on phosphorus recovery and crystal size from urine in an air-agitated reactor.

Phosphorus (P) recovery from urine is affected by various parameters. This study evaluates the effects of hydraulic retention time (HRT) and seed material on P recovery and crystal size in an air-agitated reactor. Results show that ortho-phosphate removal and struvite recovery efficiencies were 96.3% and 89.5%, and 97.1% and 93.0%, after five runs of HRTs of 1 and 2 h, respectively. Low loss of crystals from effluent urine solutions indicates high struvite recovery efficiency and is correlated with the structure and design of the reactor. The average particle size decreased from 40.0 to 31.7 µm as the HRT increased from 1 to 2 h. The two types of seed materials (zeolite and molecular sieve) did not affect the ortho-phosphate removal efficiency but affected the struvite crystal size. In particular, multi-stage addition of zeolites increased the average crystal size from 33.7 to 57.0 µm.

Effect of contact to the atmosphere and dilution on phosphorus recovery from human urine through struvite formation.

Phosphorus (P) in hydrolysed urine can be recovered through struvite formation. In the present study, batch experiments were conducted to investigate the effects of contact to the atmosphere (i.e. open and closed) and dilution [Vurine/(Vurine + Vwater)] (i.e. 100%, 50% and 25%) on P recovery from fresh urine through struvite formation with the addition of magnesium chloride (molar ratios of Mg/P = 1.3 and 2.0) after 32 d of storage. The P loss mainly occurred during the initial stages of precipitation with calcium and magnesium (5 d). The precipitates formed at the bottom of the jars were identified by X-ray diffraction to be struvite, hydroxyapatite and calcite. The results showed that the P recovery efficiency from urine solutions in open jars was lower than that in closed jars. It caused significant ammonia volatilization in open jars, resulting in higher nitrogen loss, lower pH values and lower supersaturation. The P recovery efficiency decreased with dilution, which is related to lower pH and lower supersaturation resulting from water dilution. An increase in the Mg/P ratio from 1.3 to 2.0 enhanced P recovery to some extent in urine solutions with different dilutions. The largest P recovery efficiency was 93.7% and 97.3% at an Mg/P ratio of 1.3 and 2.0 for the 100% urine solutions in closedjars, respectively. Scanning electron microscopy revealed smaller struvite particle sizes at lower dilutions (100% and 50% urine) compared with higher dilutions (25% urine).

Influence of process parameters on phosphorus recovery by struvite formation from urine.

Batch experiments were conducted to examine the influence of various process parameters on phosphorus (P) recovery by struvite formation from urine. The results showed that the Mg/P molar ratio is one of the most important parameters affecting P recovery. The Mg/P molar ratio of 1.3 was found the most reasonable for struvite formation, and the P removal efficiency reached more than 96.6%. An increase in pH of urine solutions from 8.7 to 10.0 did not significantly affect P removal, but the quality of crystal formed at pH 10.0 was poor based on scanning electron microscopy analysis. A longer mixing time positively affected struvite formation, and compared to without mixing, the P removal efficiency increased from 72.7 to 97.3% after 5 min of mixing. The addition of seed material had no influence on the P removal efficiency, but contributed to the formation of struvite clusters.

The application of zero-water discharge system in treating diffuse village wastewater and its benefits in community afforestation.

The proposed on-site zero-water discharge system was comprised of four main components: anaerobic tank, aerobic bioreactor, activated soil filter and water-collecting well. The results demonstrate that at 350 m(3) day(-1) of hydraulic load, the system can effectively remove pollutants from the wastewater, e.g., 86% removal of COD; 87% removal of SS; 80% removal of TP and 71% removal of TN. The growth states of the grasses, macrophytes and arbors in the activated soil filter were better than the control. The life of the activated soil filter was estimated to be ~12-15 yrs, based on the laboratory microcosm studies. However, humic acid contents and soil porosity have suggested that the activated soil filter was able to regenerate itself and thereby prolonging its life by reducing clogging of the pores. The results suggest that the zero-water discharge system was a promising bio-measure in treating diffuse village wastewater and benefiting community afforestation.

Eco-restoration: simultaneous nutrient removal from soil and water in a complex residential-cropland area.

An eco-restoration system to remove excess nutrients and restore the agricultural ecosystem balance was proposed and applied from August 2006 to August 2008 in a residential-cropland complex area (1.4 x 10(5) m(2)) in Kunming, western China, where the self-purifying capacity of the agricultural ecosystem had been lost. The proposed eco-restoration system examined includes three main foci: farming management, bioremediation, and wastewater treatment. The results showed that the removal efficiencies of total phosphorus (TP) and total nitrogen (TN) from the complex wastewater were 83% and 88%, respectively. The Simpson's diversity indices of macrophytes and zoobenthos indicated that the system had increased macrophyte and zoobenthic diversity as well as improved growth conditions of the plankton habitats. The results demonstrated that the proposed eco-restoration system is a promising approach for decreasing the output of nutrients from soil, improving agricultural ecosystem health, and minimizing the downstream eutrophication risk for surface waters.

Removal of cyanobacterial bloom from a biopond-wetland system and the associated response of zoobenthic diversity.

Harmful cyanobacterial bloom in water bodies frequently occurs due to eutrophication, leading to the excessive growth of cyanobacteria which in turn may lead to a decrease in biodiversity. A biopond-wetland system to control cyanobacterial bloom and stabilize or even increase biodiversity is proposed and applied in a pond, Kunming, western China where cyanobacterial blooms frequently break out. The biopond-wetland system examined includes three main parts: filter-feeding fish, replanted pond macrophytes, and a terminal artificial wetland. When the hydraulic load of the biopond-wetland system was 500m(3)/d on non-rainy days, the system successfully decreased the level of chlorophyll-a (Chl-a). The declining levels of total nitrogen (TN), total phosphorus (TP) and ammonia in the water after establishing the biopond-wetland system also coincided with the disappearance of the cyanobacterial bloom. In the second summer, when the biopond-wetland system was in a relatively steady-state condition, the overall average nutrient removal efficiencies were as follows, Chl-a (83%), TN (57%), TP (70%) and ammonia (66%), while in the second winter, the overall average removal efficiencies were Chl-a (66%), TN (40%), TP (53%) and ammonia (49%). Simpson's diversity index of zoobenthos indicated that the system increased the zoobenthic diversity and improved the growth conditions of the zoobenthos habitat. The results demonstrated that the biopond-wetland system could control cyanobacterial blooms.

[Effects of rhizosphere acidification on phosphorus efficiency in clones of poplar].

Effects of rhizosphere acidification on P efficiency in different poplar clones were conducted by the method of soil culture in greenhouse. Potassium dihydrogen phosphate was applied to furnish 0, 40, 80, and 120 mg P2O5 kg-1. The experiment consisted of three replicates of each treatment, with a pot of 40 kg soil in a randomized block. The results showed that high P efficiency clones, such as S17, S19, and 105, could decrease their pH values in rhizosphere under P deficiency stress much stronger than clones 106, 797, I-69, 1388, and 3,244, which were low P efficiency clones. The most decrement of pH for the former even accounted to 1.32 pH units and the ratios of the decrements were over 10% in comparison with the pH values in bulk soil. Whereas for the latter less than 0.21 pH units and 2.5% of the decreasing ratio respectively. In contrast to low P efficiency clones, high P efficiency clones could acidify their rhizosphere through a kind of specific mechanism because the pH values in rhizosphere of high P efficiency clones were gradually decreased corresponding with the intensity of P deficiency stress and vice versa. The amounts of available P in rhizosphere of clone S17, S19, and 105 reached 2.64, 3.27, and 3.28 mg.kg-1, respectively, obviously higher than those of the other five low P efficiency clones, which all were below 2.00 mg.kg-1 under P deficiency stress, and the summation percentages of available P in rhizosphere were over 60% for all high P efficiency clones, but less than 10% for low P efficiency clones. The amounts of P taken up by high P efficiency clones were statistically greater than by low P efficiency clones. Regression analysis also indicated that the increment of available P in rhizosphere was closely correlated with the decrement of pH values in rhizosphere under P deficiency stress. This demonstrated the impact of rhizosphere acidification on availability of rhizosphere P, and identified that high P efficiency clones could enhance their contents of available P in rhizosphere, absorb more P and thus grow better through rhizosphere acidification depended on deficiency stress.