Singlet Oxygen Formation from Wastewater Organic Matter

Singlet oxygen (¹O₂) plays an important role in the inactivation of pathogens and the degradation of organic contaminants. The present study looks at the surface steady-state concentration of ¹O₂ and quantum yields (Φ_SO) for organic matter present in or derived from wastewater (WWOM), including those that are partially treated and after undergoing oxidation. The surface steady state concentrations of ¹O₂ ranged from 1.23 to 1.43 × 10^–13 M for bulk wastewaters under simulated sunlight. The Φ_SO values for these samples varied from 2.8% to 4.7% which was higher than the values observed for the natural organic matter isolates evaluated (1.6–2.1%). Size fractionation of WWOM resulted in Φ_SO increases, with a value of up to 8.6% for one of the <1 kDa fractions. Furthermore, oxidation of WWOM by hypochlorous acid (HOCl) and molecular ozone also resulted in an increase in Φ_SO, with the highest measured value being 9.3%. This research further explores the correlations between the photosensitizing properties of WWOM and optical characteristics (e.g., absorbance, E2:E3 ratio). Making use of easily measurable absorbance values, a model for the prediction of ¹O₂ steady-state concentrations is proposed

Nanoclay-Based PVA Aerogels: Synthesis and Characterization

Nanoclay-based PVA aerogels have been synthesized at pilot-plant scale, using an environmentally friendly freeze-drying method. In the present work, the influence of different types of nanoclays on the physical, mechanical, and thermal properties of the resulted PVA aerogels were evaluated. In addition, the effect of nanoclay/PVA mass ratio was studied. Nanoclay incorporation into the polymeric matrix resulted in compact structures with small pore size distribution. Moreover, nanoclay addition (up to 3 wt %) allowed to improve the mechanical properties of the obtained aerogels. Nanoclay-based PVA aerogels showed interesting properties, such as high lightness, good mechanical properties, low thermal conductivity, and fire resistance

Nanoclay-Based PVA Aerogels: Synthesis and Characterization

Nanoclay-based PVA aerogels have been synthesized at pilot-plant scale, using an environmentally friendly freeze-drying method. In the present work, the influence of different types of nanoclays on the physical, mechanical, and thermal properties of the resulted PVA aerogels were evaluated. In addition, the effect of nanoclay/PVA mass ratio was studied. Nanoclay incorporation into the polymeric matrix resulted in compact structures with small pore size distribution. Moreover, nanoclay addition (up to 3 wt %) allowed to improve the mechanical properties of the obtained aerogels. Nanoclay-based PVA aerogels showed interesting properties, such as high lightness, good mechanical properties, low thermal conductivity, and fire resistance

Naphthoquinone Spiroketals and Organic Extracts from the Endophytic Fungus Edenia gomezpompae as Potential Herbicides

From the fermentation mycelium of the endophytic fungus Edenia gomezpompae were obtained several phytotoxic compounds including two new members of the naphthoquinone spiroketal family, namely, palmarumycin EG₁ (<b>1</b>) and preussomerin EG₄ (<b>4</b>). In addition, preussomerins EG₁–EG₃ (<b>7</b>–<b>9</b>) and palmarumycins CP₁₉ (<b>2</b>), CP₁₇ (<b>3</b>), and CP₂ (<b>6</b>), as well as ergosta-4,6,8(14),22-tetraen-3-one (<b>5</b>), were obtained. Compounds <b>2</b>, <b>3</b>, and <b>5</b> are new to this species. The structures of palmarumycins CP₁₉ (<b>2</b>) and CP₁₇ (<b>3</b>) were unambiguously determined by X-ray analysis. The isolates and mycelium organic extracts from four morphological variants of <i>E. gomezpompae</i> caused significant inhibition of seed germination, root elongation, and seedling respiration of Amaranthus hypochondriacus, Solanum lycopersicum, and Echinochloa crus-galli. The treatments also affected respiration on intact mitochondria isolated from spinach

Comparative changes in color features and pigment composition of red wines aged in oak and cherry wood casks

The color features and the evolution of both the monomeric and the derived pigments of red wines aged in oak and cherry 225 L barriques have been investigated during a four months period. For cherry wood, the utilization of 1000 L casks was tested as well. The use of cherry casks resulted in a faster evolution of pigments with a rapid decline ofmonomeric anthocyanins and a quick augmentation formation of derived and polymeric compounds. At the end of the aging, wines stored in oak and cherry barriques lost, respectively, about 20% and 80% of the initial pigment amount, while in the 1000 L cherry casks, the same compounds diminished by about 60%. Ethyl-bridged adducts and vitisins were themain class of derivatives formed, representing up to 25% of the total pigment amount in the cherry aged samples. Color density augmented in both the oak and cherry wood aged samples, but the latter had the highest values of this parameter. Because of the highly oxidative behavior of the cherry barriques, the use of larger casks (e.g., 1000 L) is proposed in the case of prolonged aging times

Metabolite Profiling of a NIST Standard Reference Material for Human Plasma (SRM 1950): GC-MS, LC-MS, NMR, and Clinical Laboratory Analyses, Libraries, and Web-Based Resources

Recent progress in metabolomics and the development of increasingly sensitive analytical techniques have renewed interest in global profiling, i.e., semiquantitative monitoring of all chemical constituents of biological fluids. In this work, we have performed global profiling of NIST SRM 1950, “Metabolites in Human Plasma”, using GC-MS, LC-MS, and NMR. Metabolome coverage, difficulties, and reproducibility of the experiments on each platform are discussed. A total of 353 metabolites have been identified in this material. GC-MS provides 65 unique identifications, and most of the identifications from NMR overlap with the LC-MS identifications, except for some small sugars that are not directly found by LC-MS. Also, repeatability and intermediate precision analyses show that the SRM 1950 profiling is reproducible enough to consider this material as a good choice to distinguish between analytical and biological variability. Clinical laboratory data shows that most results are within the reference ranges for each assay. In-house computational tools have been developed or modified for MS data processing and interactive web display. All data and programs are freely available online at http://peptide.nist.gov/ and http://srmd.nist.gov/

Metabolite Profiling of a NIST Standard Reference Material for Human Plasma (SRM 1950): GC-MS, LC-MS, NMR, and Clinical Laboratory Analyses, Libraries, and Web-Based Resources

Recent progress in metabolomics and the development of increasingly sensitive analytical techniques have renewed interest in global profiling, i.e., semiquantitative monitoring of all chemical constituents of biological fluids. In this work, we have performed global profiling of NIST SRM 1950, “Metabolites in Human Plasma”, using GC-MS, LC-MS, and NMR. Metabolome coverage, difficulties, and reproducibility of the experiments on each platform are discussed. A total of 353 metabolites have been identified in this material. GC-MS provides 65 unique identifications, and most of the identifications from NMR overlap with the LC-MS identifications, except for some small sugars that are not directly found by LC-MS. Also, repeatability and intermediate precision analyses show that the SRM 1950 profiling is reproducible enough to consider this material as a good choice to distinguish between analytical and biological variability. Clinical laboratory data shows that most results are within the reference ranges for each assay. In-house computational tools have been developed or modified for MS data processing and interactive web display. All data and programs are freely available online at http://peptide.nist.gov/ and http://srmd.nist.gov/

Metabolite Profiling of a NIST Standard Reference Material for Human Plasma (SRM 1950): GC-MS, LC-MS, NMR, and Clinical Laboratory Analyses, Libraries, and Web-Based Resources

Recent progress in metabolomics and the development of increasingly sensitive analytical techniques have renewed interest in global profiling, i.e., semiquantitative monitoring of all chemical constituents of biological fluids. In this work, we have performed global profiling of NIST SRM 1950, “Metabolites in Human Plasma”, using GC-MS, LC-MS, and NMR. Metabolome coverage, difficulties, and reproducibility of the experiments on each platform are discussed. A total of 353 metabolites have been identified in this material. GC-MS provides 65 unique identifications, and most of the identifications from NMR overlap with the LC-MS identifications, except for some small sugars that are not directly found by LC-MS. Also, repeatability and intermediate precision analyses show that the SRM 1950 profiling is reproducible enough to consider this material as a good choice to distinguish between analytical and biological variability. Clinical laboratory data shows that most results are within the reference ranges for each assay. In-house computational tools have been developed or modified for MS data processing and interactive web display. All data and programs are freely available online at http://peptide.nist.gov/ and http://srmd.nist.gov/