The objective was to establish the safety and therapeutic efficacy of oral potassium humate in reducing the signs and symptoms of hayfever. Potassium humate was randomly assigned to 40 atopic patients with acute symptoms of hayfever. Blood and nasal samples were used to determine the safety and the effects of potassium humate on basophil activation, cytokine levels and eosinophil migration. A skin prick test was used to determine its anti-allergic effects. An in vitro neutrophil adhesion was also used. A significant decrease in the skin prick test results and eosinophil counts was observed. No significant differences were observed with regard to neutrophil adhesion nor were any differences observed with regard to the stimulation of basophils. Decreases were observed in the expression of IL-4, IL-5, IL-8 and IL-1â after treatment, although not reaching significance. This study confirmed that this product possesses anti-inflammatory and anti-allergic properties possibly due to a decreased recruitment of eosinopils to the inflammatory site the recruitment and activation of eosinophils by decreasing the expression of IL-4, IL-5, IL-8 and IL-1â, although not reaching statistical significance. / Dissertation (MSc (Pharmacology))--University of Pretoria, 2008. / Pharmacology / unrestricted

Mycotoxins have become an important issue for the grain industry and animal producers with a growing interest in the decontamination and remediation of highly contaminated feedstuffs. Practical methods to detoxify mycotoxin-contaminated grain on a large scale and in a cost-effective manner are essential but not currently available. The most recent and promising approach to detoxify mycotoxin-contaminated grain is the use of non-nutritive adsorbents, which bind the aflatoxin and thereby reduce their absorption from the gastrointestinal tract. Humic acids are products of chemical and biological transformations of animal and plant residues and are widely distributed in nature. Humic acids have some therapeutic characteristics and a strong binding affinity for several compounds. A South African company developed an effective large-scale regeneration process for humic acids from coal, called oxihumate. This study evaluated the effectiveness of oxihumate to adsorb mycotoxins, for the purpose of developing it as a commercial mycotoxin binder to be used in the preventative management of contaminated poultry feedstuffs. The in vitro affinity and adsorption capacity of oxihumate to aflatoxin was evaluated and the efficacy of oxihumate as an aflatoxin binder in broiler feeds in vivo was determined. The data showed adsorptions of about 10.3, 7.4 and 11.9 mg aflatoxin B1/g oxihumate at pH 3, 5 and 7, respectively. Oxihumate adsorbed 1.2, 2.6 and 8.5 mg aflatoxin G2/g at pH 3, 5 and 7, respectively. Oxihumate supplementation at a concentration of 3.5 g/kg feed was effective in diminishing the growth inhibitory effects of aflatoxin and apparent protection was noted for some of the organ, haematological and serum biochemical changes associated with aflatoxicosis. These results suggest that oxihumate could alleviate some of the toxic effects of aflatoxin in growing broilers, and when used with other sound mycotoxin management practices, might prove beneficial in the preventative management of aflatoxin-contaminated feedstuffs for poultry. The improvement observed during this specific study was, however, not satisfactory enough to recommend oxihumate as a commercially available product. / Thesis (PhD (Animal and Wildlife Sciences))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

A series of experiments were performed to study the sorption of humic acid and Eu3+ ion (at trace concentrations) on the minerals: montmorillonite, bentonite, diatomite and kaolinite in ternary systems. Humic acid and europium sorption were investigated as a function of humic acid concentration, ionic strength and pH. There was a strong uptake of humic acid on to the minerals with sorption increasing as humic acid concentration decreases. For montmorillonite, the uptake of discrete size fractions was also studied. It was found that the larger fractions were more strongly sorbing and were better able to retain Eu in solution.The ionic strength has an impact on Eu behaviour: in the absence of humic acid, sorption strength decreases, whilst in the presence of high concentrations of humic it increases. The sorption of Eu3+ increases from pH 2 to 5 in both the presence and absence of humic acid. Above pH 5, the Eu3+ showed different behaviour with and without humic acid, and as humic concentration became high (100 ppm), the Eu behaves in the same way as the humic. Bentonite is able to sorb humic acid and Eu3+ at any concentration expected in the environment, and shows the strongest sorption of any of the materials tested. Experiments confirmed that Eu is an excellent analogue for Am in these systems.The sorption of selected divalent and trivalent metal ions: Ni2+, Co2+, Zn2+, Cd2+, Eu3+ and Cr3+ on montmorillonite has been investigated in the micro-molar concentration range. In all cases, sorption strength increased with pH, and was consistently stronger for the tri-valent ions. In the presence of humic acid, there was some evidence for the enhancement of sorption. Uptake of metal ions (Co2+, Ni2+, Cd2+, Cr3+, Eu3+ and La3+) by natural and modified kaolinite was studied, and for all except Cr3+, it was found that kaolinite modified by manganese hydrothermal treatment gave the strongest sorption.A simple kinetic model was developed to simulate the experimental data for the sorption of humic acid and Eu3+ on the minerals. The model allows two humic binding sites on the mineral surface and two types of humic in solution, which can have different Eu3+ binding strengths. Metal ion surface complexation is modelled with a single kinetic equation. Ternary complexes are included in the model. The interaction of humic acid on the minerals can be fitted reasonably well. However, for the Eu3+ ion behaviour, although the model was able to give a reasonable fit to data for montmorillonite and bentonite, it could not reproduce the behaviour for kaolinite and diatomite.

The diploma thesis deals with lignitic humic acids. Bibliographic search can be divided into three parts. The aim of the first part is characterization of humic substances, presence, composition, structure and exploitation especially of humic acids. The second part describes a division of heterogeneous mixture of humic acids into closed fractions with more specific properties. The final part is a study of solubility of humic acids. The experimental part of the diploma thesis is structured similarly. In this work, a gradual fractionation with pH is used. Obtained fractions were characterized by UV/VIS and FT-IR spectroscopy. We assessed the portion of ash and carboxyl groups have been identified. Subsequently, all fractions extracted by gradual fractionation as well as some soluble fractions obtained by direct fractionation have been analyzed in view of solubility and their behaviour in water environment. Both used methods were compared.

No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24104号 / 工博第5026号 / 新制||工||1784(附属図書館) / 京都大学大学院工学研究科原子核工学専攻 / (主査)教授 佐々木 隆之, 教授 横峯 健彦, 准教授 小林 大志 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This work involves the combination of chelation and microwave extraction as a technique for extracting adsorbed metals in soil. It has been termed in this work, Chelate Assisted Microwave Extraction (CAME). Unlike other extraction methods, CAME is able to differentiate between anthropological and geological trace metals. The method has been applied to major sample matrices included three types of soils (Bertie Sandy Loam, Davidson Silty Clay, and Davidson Clayey Loam) as well as sea sand, alumina, and iron oxide. In order to investigate the effects of sorptive coatings on metal concentrations, a sample set was first treated with humic acids, which represented organic coated materials. Afterwards, copper (II) solutions were spiked to both untreated and treated matrices and the efficiencies of recoveries were studied. Metal determinations were performed by Inductively Coupled Plasma-Atomic Emission Spectrophotometry (ICP-AES). Initial studies of control (untreated soil) and long-term Cu amended (spiked) Bertie Sandy Loam (BSL) indicated that extraction efficiencies were method dependent. Ethylenediaminetetraacetic acid (EDTA) was a primary chelating agent used for method comparisons. Extracting solutions having a pH range from 7.8 to 10.1 did not affect the EDTA-microwave method, but the increase in pH enhanced Cu removal by the EDTA-shaking extraction method which was a conventional chelation using a mechanical shaker. With the EDTA-microwave method, complete extraction was achieved in a short period of time (20 minutes). Compared to the EDTA-shaking method using two sandy soils, the EDTA-microwave method proved to be more efficient in extracting sorbed metals in soils (5.9 vs. 4.6 µg/g for the control BSL and 37.5 vs. 27.8 µg/g for the amended BSL. FT-IR and C13 NMR were used to characterize extracted and commercially available humic acids. The latter was employed to prepare the humate coated materials. Iron oxide containing materials such as Davidson Silty Clay (DSC), Davidson Clayey Loam (DCL), and iron oxide (Fe2O3), showed extremely high adsorption capabilities for humic acids, while sea sand, Bertie Sandy Loam, and alumina (Al₂O₃) provided lower adsorption capabilities for humic acids. Two sets of uncoated and humate coated materials were used for Cu spiking procedures using 0.001 M Cu (II) at pH 5.3 for 24 hour-equilibration. Three original soils and alumina showed high adsorption capabilities for Cu (II). The presence of coated humate helped increase Cu adsorption capabilities of these soils, but diminished the ability of alumina to react with Cu (II) ions. For HA-uncoated matrices, iron oxide had a higher Cu adsorption capability than sea sand but less than real soils. Humate coating improved Cu adsorption capabilities of not only real soils but iron oxide and sea sand as well. Lastly, the developed method named Chelate Assisted Microwave Extraction (CAME) was further examined and optimized. Several samples were investigated for extraction efficiencies. A two-step extraction, applying 120 W for 5 min followed by 60 W for 10 min, was efficient in removing sorbed metals from different matrices regardless of sorptive oxide and organic components. Concentrations of chelating agents slightly affected percent metal removal; however, there was no significant difference in results obtained using EDTA or diethylenetriaminepentaacetic acid (DTPA). Recoveries of spiked metals (Cu and Cd) ranged from 96 to 107%. Using the untreated (control) Davidson Silty Clay and Bertie Sandy Loam, the comparison of other chelating solutions were made. Clearly, CAME was promising and proved to be a good alternative to classical shaking method for extracting adsorbed metals from soils. / Ph. D.

Agroecosystem and cycling loops are open when considering the reutilization of inputs in farming areas. Non-renewable resources have been transformed or relocated from the air, water and land into the system and are flowing out as wastes rather than reusable, recyclable resources. Therefore, current trends in agriculture have moved towards more sustainable cultivation systems with higher efficiency of input use, since mineral nutrient losses due to runoff, leaching, erosion and gas emissions are leading to environmental degradation. A huge variety of materials can serve as a crop nutrient supply and they can be derived from different resources. The integrated plant nutrition system (IPNS) thrives tailoring plant nutrition and soil fertility management, taking advantage of the conjunctive and harmonious use of inorganic, organic and biological resources. We hypothesize that the synergetic effects of the combination of humic acid HA + biofertilizer will improve plant agronomic outcomes when comparing the application of each product alone. We initiated this project conducting a greenhouse study and field experiments evaluating the effects of an IPNS on corn. Posteriorly, the positive results in terms of corn biomass increasing, led to another greenhouse study addressing cannabis (Cannabis sativa L.) due its valuable biomass as an end/selling product. The greenhouse studies evaluated the effects of commercial synthetic fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively, and their synergy on corn and cannabis early development under a period of water deficit stress. Generally, for both studies, when compared to the control values, the use of HA, biofertilizers and the integration of both substances generated significantly greater early season plant height, chlorophyll content and photosynthetic efficiency. The three-year field trial investigated the effects of nitrogen (N) fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively and their synergy on corn growth. The individual and integrated application of HA and biofertilizer generally influenced corn development, to varying degrees. In 2017, corn height, NDVI, greenness and vigor were sensitive to the application of these biostimulants in different magnitudes and growth stages, however grain yield and nutrient content were not affected. In combined studies from 2018 and 2019 corn height was not impacted by biostimulant application but NDVI, photosynthetic efficiency, greenness and vigor were affected at different doses and corn growth stages. Only one treatment integrating HA + biofertilizer led to increased grain yield. In sum, these studies provided evidence that the individual and combined application of HA and biofertilizer can positively influence corn and cannabis growth most likely due to their plant biostimulant effects. However, the current study cannot conclusively affirm that the integrated use of HA and biofertilizers following the IPNS is a superior practice than the application of each compound individually and further studies should be conducted to validate these findings. / Doctor of Philosophy / The status of the corn (Zea mays L.) demand in Virginia and the Mid-Atlantic region is currently in deficit regarding the production in this area. This demand is exceeding supply by approximately 150%, then increasing feed grain yield and consequently production in the region can be simultaneously beneficial to crop farmers, end-users and the entire food supply chain. Furthermore, the consumer market is becoming more aware about sustainable practices for food production, which encourages producers to adopt agricultural practices that can minimize negative environmental impacts. This scenario enforces the scientific community's responsibility to test and develop environmental-friendly methods able to increase fertilization efficiency, decreasing the use in synthetic inputs but maintaining yield. The integrated plant nutrition system (IPNS) implements the combined and harmonious use of inorganic, organic and biological resources to take advantage of the potential synergetic effects. We conducted greenhouse studies and field experiments evaluating the effects of an IPNS on corn, and posteriorly based on the preliminary results obtained with corn, a greenhouse study addressing cannabis (Cannabis sativa L.) was also carried out. The greenhouse studies evaluated the effects of commercial synthetic fertilizer, humic acid (HA), compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively, and their synergy on corn and cannabis growth under a period of drought. Generally, for both studies, when comparing to the control values, the use of HA, biofertilizers and the integration of both compounds generated significantly greater early season plant height and photosynthesis measurements. The three-year field trial investigated the effects of nitrogen (N) fertilizer, HA, compost/manure teas and bioinoculant as inorganic, organic and biological resources, respectively and their synergy on corn growth. The individual and combined application of HA and biofertilizer generally influenced corn development, to varying degrees. In 2017, corn height, vegetation index, greenness and vigor were sensitive to the application of these biostimulants in different magnitudes and growth stages, however grain yield and nutrient content were not affected. In combined studies from 2018 and 2019 corn height was not impacted by biostimulant application but vegetation index, photosynthetic efficiency, greenness and vigor were affected at different doses and corn growth stages. Only one treatment combining HA + biofertilizer led to increased grain yield. In sum, these studies provided evidence that the individual and combined application of HA and biofertilizer can positively influence corn and cannabis growth most likely due their plant biostimulant effects. Even though, the current study cannot affirm that the combined use of HA and biofertilizers following the IPNS is a better practice than the application of each compound individually, this practice can be a more sustainable alternative to fit in the conventional farming scene.

A four-year drought, increasing population and shifting climate has spurred water conservation practices within Virginia. Creeping bentgrass (<i>Agrostis palustris</i> "L93"), Kentucky bluegrass (<i>Poa pratensis </i>"Midnight"), and tall fescue (<i>Festuca arundinacea</i>) Dominion blend were evaluated under deficit irrigation and upon exogenous application of plant growth stimulants (PGS), seaweed extract (SWE) + humic acid (HA), glycinebetaine (GB) and a commercial SWE product (PP). The objectives were to determine crop coefficients (K_c) for creeping bentgrass fairways and tall fescue home lawns, to determine if PGS application allowed for more water conservation, and to determine if they impacted physiological function and/or root morphology. A preliminary greenhouse experiment was conducted with creeping bentgrass and Kentucky bluegrass irrigated with 100%, 85% and 70% of evapotranspiration (ET). The study determined that an additional deficit irrigation level should be included for the field study and that GB application and 100% and 85% ET irrigation level produced the greatest creeping bentgrass root mass. The two–year field study evaluated creeping bentgrass and tall fescue. Tall fescue home lawns could be irrigated every five days with a K_c of 0.55 or once a week with a K_c of 0.70. Creeping bentgrass fairways could be irrigated every four days with a K_c of 0.85. Glycinebetaine application increased bentgrass rooting after planting and showed osmoprotectant properties. Another greenhouse study evaluated five GB rates on bentgrass and tall fescue. No differences were found between the five rates and concluded that the rate utilized in the field study may be appropriate for turfgrass application. / Master of Science

The focus of this research was to acquire a better understanding of the sorption and desorption of pentachlorophenol to soil organic matter. In order to separate the reactions controlling the interactions with the soil organic matter from those associated with mineral surfaces, these experiments used only humic acids extracted from soil samples. The major focus of this study was to examine the effects of solution pH, humic acid concentration and contact time on the degree of sorption. The association reactions proceeded slowly. Even after 28 days, many solutions had not attained equilibrium. An increase in the solution pH led to a reduction in the amount of partitioning onto the humic material. At solution concentrations between 100 mg/L and 800 mg/L of total organic carbon (TOC), an increase in the humic acid concentration resulted in a lower partition coefficient. However, above a concentration of 800 mg/L TOC, further increases in the amount of humic material caused enhanced sorption. The particulate humic acids demonstrated a higher affinity for the pentachlorophenol than did the dissolved polymers. In the concentrated solutions, the majority of the humic acids were present in the particulate form. Two experiments focused on the effect of sorption on the bioavailability and solvent extraction of pentachlorophenol. The bioavailability data Suggested that the sorbed contaminant was not readily accessible to the microorganisms. The humic acids prevented the extraction of the sorbate by methyl-tert-butyl ether and methylene chloride. Recovery of the pentachlorophenol sorbed to the dissolved humic acids ranged from zero to 42.9 percent, depending on the solution pH. The removal of pentachlorophenol from the particulate matter varied from 25 percent to 90 percent. Longer contact times diminished the transfer of PCP associated with the solid humic acids to the solvent phase. The experimental results were not consistent with a simple, one mechanism model. The best explanation of the data was provided by a model which included liquid-liquid partitioning, surface sorption, absorption, and chemisorption. The dominant process depended on the contact time, solution pH, and concentration and nature of the humic acids. / Master of Science