Influence of temperature on performance of an anaerobic sequencing biofilm batch reactor with circulation applied to treatment of low-strength wastewater

The effect of temperature on the performance of an anaerobic sequencing biofilm batch reactor (ASBBR) with liquid-phase recirculation was assessed. Assays were performed using a recirculation velocity of 0.20 cm/s, 8-h cycles, and an average treated synthetic wastewater volume of 2 L/cycle with a concentration of 500 mg of Chemical Oxygen Demand (COD)/L. Operation temperatures were 15, 20, 25, 30, and 35°C. At 25, 30, and 35°C, organic matter removal efficiencies for filtered samples ranged from 81 to 83%. At lower temperatures, namely 15 and 20°C, removal efficiency decreased significantly to 61 and 65%, respectively. A first-order model could be fitted to the experimental concentration profile values. The first-order kinetic parameter value of this model varied from 0.46 to 0.81 h¹ considering the lowest and highest temperature studied. Moreover, analysis of the removal profile values allowed fitting of an Arrhenius-type equation with an activation energy of 5715 cal/mol.     

Synthesis and temperature dependence of physical properties of four pyridinium-based ionic liquids: Influence of the size of the cation

In this paper, the ionic liquids 1,2-diethylpyridinium ethylsulfate, EEpyESO₄; 1-methylpyridinium methylsulfate, MpyMSO₄; 1,3-dimethylpyridinium methylsulfate, MMpyMSO₄; and 2-ethyl-1-methylpyridinium methylsulfate, EMpyMSO₄; were synthesized in our laboratory, and their experimental densities, speeds of sound, dynamic viscosities, and refractive indices were studied as a function of temperature at atmospheric pressure. Thermal expansion coefficient, molar volume, and molar refraction of these ionic liquids were calculated from the experimental density and refractive index values.     

Cladonia verticillaris (lichen) can exhibit defense mechanisms against Rn-222 under controlled conditions

Journal of Radioanalytical and Nuclear Chemistry - This study aimed to evaluate the effects of the Rn-222 progeny on the lichen Cladonia verticillaris under controlled conditions. The results...     

Quantitative analysis of amino acids by HPLC in dried blood and urine in the neonatal period: Establishment of reference values

Quantitative analysis of amino acids in blood and urine is primarily indicated for the diagnosis of amino acid disorders. The high-performance liquid chromatography (HPLC) technique is frequently used for this detection. The frequency of sample collection on filter paper has been increasing exponentially, and there are many advantages attributed to processing biological samples in this way. The aim of this study was to validate a quantitative analysis of amino acids by HPLC in blood and urine collected on filter paper and to establish reference values in the neonatal period. Dried blood and dried urine samples of respectively 58 and 45 healthy newborns (2–9 days) were collected. Pre-treatment and extraction of samples were done according to the literature. Separation and analysis of amino acids were carried out by HPLC with fluorescence detection. The developed method demonstrated excellent separation, linearity, limits of detection and quantification, repeatability and recovery. The reference values for 17 amino acids were defined in dried blood and urine samples of newborns. This work presents a simple, fast and effective method for the simultaneous analysis of 17 amino acids in blood and urine collected on filter paper in a single run. The reference values were established and validated.     

Synthesis and photophysical evaluation of meso-phenyl-1,4-dihydropyridineand pyridine-porphyrin hybrids

Chemistry of Heterocyclic Compounds - In the present work, we have synthesized new molecular hybrids consisting of porphyrin ring system connected at the meso positions with phenyl groups and/or,...     

ESI-MS differential fragmentation of positional isomers of sulfated oligosaccharides derived from carrageenans and agarans

We have prepared a number of isomeric red seaweed galactan-derivative sulfated oligosaccharides to determine whether there were diagnostic differences among the isomeric mass spectra obtained using ESI CID MS/MS (triple quadrupole instrument). Fragmentation of the single or multicharged molecular ions from di-, tetra-, and hexasaccharides indicated that the relative positioning of the sulfate groups and type of monosaccharide unit affect the rate of cleavage of the glycosidic bonds. We also performed a comparative [M-Na]⁻ fragmentation study of positional isomers of sulfated disaccharides that present all four monosulfation possibilities on the galactopyranosidic ring. In this case, negative-ion ESI CID MS/MS approach gave diagnostic product ions from cross-ring cleavages along with the same main B₁ ion (from sulfated Gal_p), at m/z 241, for all isomers. The isomeric disaccharides were also submitted to increased spray energy conditions inducing in-source fragmentation; preformed B₁ ions were then fragmented to give similar product ions as those found in [M-Na]⁻ analysis. Evaluation of the relative abundances mainly for cross-ring fragment ions at m/z 138, 139, 151, 153 allowed clear distinction among the members of the disaccharide series. The different ratios for m/z 151/153 ions were consistent with the predominance of m/z 153 being related to the cases when the bond involved in the cleavage process links a sulfated carbon. A quadrupole ion trap instrument (MSⁿ analysis) was also utilized to compare the results obtained with the triple quadrupole instrument.     

Aminodi(hetero)arylamines in the thieno[3,2-b]pyridine series: synthesis, effects in human tumor cells growth, cell cycle analysis, apoptosis and evaluation of toxicity using non-tumor cells

Three aminodi(hetero)arylamines were prepared via a palladium-catalyzed C-N Buchwald-Hartwig coupling of methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate with different bromonitrobenzenes, followed by reduction of the nitro groups of the coupling products to the corresponding amino compounds. The aminodi(hetero)arylamines thus obtained were evaluated for their growth inhibitory effect on four human tumor cell lines MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), NCI-H460 (non-small cell lung cancer) and HepG(2) (hepatocellular carcinoma). The toxicity to non-tumor cells was also evaluated using a porcine liver primary cell culture (PLP1), established by us. The aminodi(hetero)arylamine with the NH(2) group in the ortho position and an OMe group in the para position to the NH of the di(hetero)arylamine, is the most promising compound giving the lowest GI(50) values (1.30-1.63 μM) in all the tested human tumor cell lines, presenting no toxicity to PLP1 at those concentrations. The effect of this compound on the cell cycle and induction of apoptosis was analyzed in the NCI-H460 cell line. It was observed that it altered the cell cycle profile causing a decrease in the percentage of cells in the G0/G1 phase and an increase of the apoptosis levels.     

1H NMR-based metabolomics approach for exploring urinary metabolome modifications after acute and chronic physical exercise

Metabolomics is a comprehensive method for metabolite assessment that involves measuring the overall metabolic signature of biological samples. We used this approach to investigate biochemical changes due to acute and chronic physical exercise. Twenty-two women using identical oral contraceptives were segregated into an untrained (n = 10) or trained (n = 12) group depending on their physical training background. The subjects performed two exercises in a randomized order: a prolonged exercise test (75% of their \mathop V^· \textO_2   max \mathop V\limits^\cdot {{\text{O}}_{2\,\;\max }} until exhaustion) and a short-term, intensive exercise test (short-term, intensive exercise anaerobic test). Urine specimens were collected before and 30 min after each test. The samples were analyzed by ¹H NMR spectroscopy, and multivariate statistical techniques were utilized to process the data. Distinguishing characteristics were observed only in the urine profiles of specimens collected before vs. 30 min after the short-term, intensive exercise test. The metabolites responsible for such changes were creatinine, lactate, pyruvate, alanine, β-hydroxybutyrate, acetate, and hypoxanthine. In both groups, the excretion of lactate, pyruvate, alanine, β-hydroxybutyrate, and hypoxanthine increased similarly after the completion of the short-term, intensive exercise test (p < 0.03). However, acetate excretion increased to a lesser extent in trained than in untrained subjects (p < 0.05). In conclusion, metabolomics is a promising tool in order to gain insight into physiological status and to clarify the changes induced by short-term, intense physical exercise.