Water-soluble Levels Research Articles

Soil-derived organic particles and their effects on the community of culturable microorganisms.

Soil microbial community interacts with a range of particulate material in the soil, consisting of both inorganic and organic compounds with different levels of water solubility. Though sparingly water-soluble and insoluble organic compounds in the soil may affect living organisms, they are difficult to introduce into microbiological media. Their biological activity (i.e., their effect on soil microorganisms) thus has been almost neglected in most of the cultivation assays. To fill this gap, we propose the use of fine organic particles prepared from soil organic matter that are introduced into a laboratory medium where microbial community is cultivated. To this purpose, submicrometer particles consisting of sparingly water-soluble or insoluble soil organic matter were obtained from humic horizons of two soils by precipitation of organics dissolved in tetrahydrofuran by addition of water. The particles could then be size fractionated by centrifugation, and coarse fraction obtained from humic horizon formed under spruce forest was tested for effects on complex microbial community developing under laboratory conditions. The results indicate that low concentration (20mg/L) of the particles is efficient to affect the composition of the bacterial community revealed by terminal restriction fragment length polymorphism. The work contributes to understanding the factors that determine the composition of soil microbial community.

Combined sonochemical and short-wavelength UV degradation of hydrophobic perfluorinated compounds

Perfluorochemicals (PFCs), which are common in the aquatic environment, are toxic substances that have high chemical and heat resistance because of their strong C-F bonds. We investigated the effect of ultrasonication and short-wavelength UV irradiation on the degradation of perfluorooctane, perfluoropropionic acid, and perfluorooctanoic acid, which are examples of hydrophobic, hydrophilic, and intermediate PFCs, respectively. The results confirmed that ultrasonication was more effective for decomposing hydrophobic PFCs and UV irradiation was more effective for decomposing hydrophilic PFCs. Therefore, defluorination of the degradation intermediates was improved by a combination of ultrasonication and UV irradiation. Our results can be applied to the decomposition treatment of PFCs that have various levels of water solubility in the aquatic environment.

Derivates of azaphilone Monascus pigments

Progress Research on Monascus pigments has been very rapidly, includes the discovery of new pigments and methods used for the isolation and identification of new pigments. Currently, nearly fifty seven new pigments have been found which are derivatives of the six main pigments that already exist. The process of discovery of new pigments can not be separated from the process which are carried out during fermentation or during the isolation. This review includes data from all fifty new pigments following chemical structure data, chemical formula, the level of water solubility, the value of Log P, Monascus strain, substrates used in the fermentation process and methode to identification. Data collected from various studies that have been done before, and added with some of the new data. The aim of this review is to give more comprehensive data about Monascus pigments.

Some novel organometallic MnIII complexes with porphine and 1,6-diaminohexane

A novel series of MnIII complexes with 5,10,15,20-tetra(p-tolylporphine) and 1,6-diaminohexane has been synthesized. These complexes have been characterized by UV/Vis, IR, ESI-mass spectra, elemental analysis, conductivity and magnetic susceptibility measurements. These MnIII porphyrins exhibited a blue shift in soret band in comparison to non-metallated porphyrins. The molar conductance values of these complexes show their non-electrolytic nature in ethanol. The tentative structures have also been proposed. All the complexes have good level of water solubility due to which they may have medicinal as well as other valuable biological applications.

Environmental properties of long-chain alcohols, Part 2: Structure–activity relationship for chronic aquatic toxicity of long-chain alcohols

Daphnia magna reproduction tests were performed with C 10, C 12, C 14 and C 15 alcohols to establish a structure–activity relationship of chronic effects of long-chain alcohols. The data generation involved substantial methodological efforts due to the exceptionally rapid biodegradability of the test substances and the need to test as close as possible to their water solubility limits. Test concentrations were determined by GC–MS before and after test solution renewal. Whereas apparent toxicity based on survival and reproduction increased with increasing C-chain lengths up to C 14, observations of toxicity to C 15 alcohol were not in line with lower chain lengths due to the lack of toxicity below the level of water solubility. When omitting C 15, the slope of most (Q)SARs approach −1, being consistent with the expectation of a non-polar narcotic mode of action. Further testing at higher chain lengths is not sensible due to progressively lower solubility, at remaining biodegradability. Effects on mortality and reproduction are not expected below the level of water solubility.

Exchange of iron from chelate in the fertilizer against copper, manganese, and zinc in peaty substrates

To overcome iron (Fe) deficiency in horticultural crops, particularly for those crops very susceptible and exhibit marked leaf chlorosis, a new base fertilizer for peaty substrates was introduced with an Fe content (as EDTA chelate) of 0.35%. The fertilizer used normally had 0.09% Fe. With the new fertilizer, higher Fe contents in water extracts were found than before, but also unexpectedly high extract levels of manganese (Mn) and zinc (Zn) were recovered, although the Mn and Zn contents in the new fertilizer were unchanged. The copper (Cu) content of the new fertilizer has been doubled, but the levels recovered in extracts were far more than double. The assumption that accounts for this phenomenon was that the chelate extracted Cu, Mn, and Zn from the peat and the lime. To prove this hypothesis, Fe‐EDTA was added to a black and white peat in amounts comparable to those used in horticultural practice with different lime additions. Iron, Mn, Zn, and Cu were analysed in the standard 1:1.5 volume water extract In order to test the stability of the EDTA chelate, the more stable EDDHA chelate was also used. When Fe chelates were added to peaty substrates, the Mn, Zn, and Cu contents in the water extracts were increased, even without the addition of these micronutrients. This effect was more pronounced when: a) the pH was high: b) a white peat was used rather than a black peat, and c) more with Fe‐EDTA than Fe‐EDDHA. So the hypothesis proved to be of value. The addition of chelates in fertilizers should not exceed certain limits and their pH stability should be considered because they may act as an extractant, thus elevating the water soluble levels of Mn, Zn, and Cu recovered from the substrate and perhaps to toxic concentrations that could affect plant production. Furthermore, the phenomenon should be taken into account with the interpretation of Fe, Mn, Zn, and Cu contents in water extracts of substrates which have been fertilized with chelates.

Relationship between water soluble and exchangeable soil cations for estimating plant uptake and leaching potential

Abstract The relationship between water soluble and exchangeable cations (Ca, Mg, Na, and K) was investigated for surface horizons of 195 soils including many taxonomic categories and a wide range in physical and chemical properties from around the world. This will provide information on exchangeable soil cation solubility for use in estimating plant uptake and leaching potential. Amounts of water soluble and exchangeable cations were not consistently related (r2 of 0.50, 0.08, 0.77, and 0.49 for Ca, Mg, Na, and K). High correlations were biased by high water soluble and exchangeable cation levels of a few soils that had 3.8‐ and 2.5‐fold greater mean than median values. The ratio of exchangeable to water soluble cations was closely related to cation saturation (r2 of 0.87, 0.95, 0.95, and 0.93 for Ca, Mg, Na, and K, respectively). As the degree of saturation of the exchange complex by a certain cation increased, solubility Increased. A change in saturation had less effect on K than on Na, Mg, and Ca solubility. Only exchangeable soil cations (NH4OAc extractable) are routinely measured and reported in soil survey reports, thus, water soluble levels may be determined from cation saturation. This will allow estimation of the amounts of cation that can potentially move in solution through the soil or be taken up by plants. Use of cation saturation, in addition to exchangeable content, will better characterize soil cation availability by representing quantity, intensity, and buffer factors.

Radiation processed PAA composites for endosseous implants

A new porous polymer-ceramic composite has been developed in this laboratory for use in bone restoration. The alumina-poly (acrylic acid) composite was developed by the polymerization of an aqueous acrylic acid solution in the presence of 0.3μ alumina powder. The polymerization was initiated by exposing the above mixture to gamma radiation at a dose rate of 0.24 Mrad/hr for a total dose of one Mrad. The radiation step was followed by a heat treatment step to drive the excess water out of the system and create the interconnecting porosity necessary for bone ingrowth. The porosity of the PAA-alumina composites was varied from 30–60 vol. % by adjusting the monomer concentration. Mechanical testing indicated ductile behavior with compressive yield strengths of 69 MPa and 125 MPa at 60 and 30 vol. % porosity respectively. The degree of cross-linking of the PAA matrix can be varied to induce different levels of water solubility thereby allowing the equilibrium water absorption to be easily controlled. When the polymer matrix was crosslinked to 60, 80 and 95%, composite swelling in water was 50, 25 and 15 vol. % respectively. Corresponding changes in mechanical properties as a function of crosslink density will also be presented. The ability to control the composite's properties allows a variety of implant applications such as endosseous root implants and ridge augmentation. Preliminary results for endosseous implants in dogs showed material biocompatibility and ease of body fluid diffusion. In addition, a distinct advantage of this material is its ease of fabrication and adaptation to various socket geometries. Implantation experiments are now in progress to determine the long term behavior of the material.