Finite-size effects on the phase transition in a four- and six-fermion interaction model

We consider four- and six-fermion interacting models at finite temperature and density. We construct the corresponding free energies and investigate the appearance of first- and second-order phase transitions. Finite-size effects on the phase structure are investigated using methods of quantum field theory on toroidal topologies.     

New approach for the clinical monitoring of 25‐hydroxyvitamin D3 and 25‐hydroxyvitamin D2 by ultra high performance liquid chromatography with MS/MS based on the standard reference material 972

Biomarkers, 25‐hydroxyvitamin D₃ and 25‐hydroxyvitamin D₂, are important indicators of the vitamin D general status and are monitored in several pathophysiological disorders, such as osteoporosis, diabetes, heart disease, etc. A novel ultra‐HPLC with MS/MS methodology for the analysis of 25‐hydroxyvitamin D derivatives coupled with a very simple and highly rapid sample preparation step was developed. Analytical parameters obtained showed linearity (R²) above 0.999 for both vitamins with accuracies between 95.8 and 102%. The LODs were as low as 0.22 and 0.67 nmol/L for 25‐hydroxyvitamin D₃ and 25‐hydroxyvitamin D₂, respectively. Intra‐assay precision (%RSD) was lower than 4.5%, and inter‐assay precision (%RSD) was lower than 6.5%. The feasibility of the developed methodology to be applied in clinical routine analysis has been proved by its application in blood samples from non‐agenarian patients, patients with familial hypercholesterolemia and patients suffering from age‐related macular degeneration.     

Herbal medicine physical quality evaluation by thermal analysis using adapted Ozawa method

Journal of Thermal Analysis and Calorimetry - The aim of this study was to evaluate the physical quality of Tabebuia caraiba (Mart.) Bur. powder, separately in three batches of different particle...     

A New Extraction and Purification Methodology of Bowman-Birk Inhibitors from Seeds and Germinated Seeds of Macrotyloma axillare

The Macrotyloma axillare Bowman-Birk inhibitors from seeds and germinated seeds (120 h) were purified by an alternative methodology and revealed the presence of different contents of inhibitors for each treatment. Mass analyses of inhibitors, from seeds and germinated seeds, showed masses of about 7 and 8 kDa. The 120 h-germinated seed fractions presented higher activity isoforms than seeds without treatment.

     

Determination of 5‐fluorocytosine, 5‐fluorouracil,and 5‐fluorouridine in hospital wastewater by liquid chromatography–mass spectrometry

Chemotherapeutics are pharmaceutical compounds the occurrence of which in the environment is of growing concern because of the increase in treatments against cancer diseases. They can reach the aquatic ecosystems after passing through wastewater treatment plants without complete removal. One of the most frequently used chemotherapeutics is 5‐fluorouracil which exhibits a strong cytostatic effect. In this paper, an analytical methodology was developed, validated, and applied to determine 5‐fluorouracil, its precursor, 5‐fluorocytosine, and its major active metabolite, 5‐fluorouridine, in hospital wastewater samples. Due to the expected low concentrations after dilution and interferences present in such a complex matrix, a very selective and sensitive detection method is required. Moreover, an extraction method must be implemented prior to the determination in order to purify the sample extract and preconcentrate the target analytes at micrograms per liter concentration levels. Solid‐phase extraction followed by liquid chromatography with tandem mass spectrometry was the combination of choice and all included parameters were studied. Under optimized conditions for wastewater samples analysis, recoveries from 63 to 108% were obtained, while intraday and interday relative standard deviations never exceeded 20 and 25%, respectively. Limits of detection between 61 and 620 ng/L were achieved. Finally, the optimized method was applied to samples from hospital wastewater effluents.     

Partially carboxymethylated cotton dust waste for sorption of textile wastewater coloured with the cationic dye Basic Blue 41 as a model: synthesis,regeneration and biodegradability

The removal of residual dyes in coloured textile wastewaters is mandatory, and a significant portion of the dyes used are cationic. Textile factories mainly process cotton yarns, and 8 % of this virgin feedstock is lost as cotton dust waste (CDW). Using factorial experimental design, this dust was derivatised with monochloroacetic acid (MCAA) to produce a partially carboxymethylated cellulose (CM^?-CDW) with NaOH, MCAA and isopropanol for the retention of Basic Blue 41 dye (BB 41) (column and batch), and biodegradability was investigated. The dye retention efficiency was examined with additional experiments varying the initial concentration, contact time and addition of salts. Heteronuclear multiple bonding correlation-nuclear magnetic resonance confirmed the covalent insertion of CM^? groups in the cellulosic fibres. The selected matrix provided a dye sorption of 58.33 (column) and 64.50 mg/g (batch). The Langmuir isotherm was a good fit to the sorption data. The efficiency of uptake of BB 41 was predominantly dictated by the concentration of alkali in the matrix synthesis. Biodegradability by cellulases was similar when using uncharged and dye-charged matrices. The latter were fully regenerated by washing in dilute acid. Retention was proportional to the initial dye concentration and the contact time required to reach equilibrium, which was longer for higher dye concentrations. The addition of 10 mmol/l NaCl decreased BB 41 retention by 50 %. Therefore, CM^?-CDW proved effective for the removal of the cationic dye BB 41 and thus represents an important alternative in the treatment of coloured textile effluents.     

Structural Modifications and Solution Behavior of Hyaluronic Acid Degraded with High pH and Temperature

Applied Biochemistry and Biotechnology - 99mTc-ciprofloxacin scintigraphy is useful in the detection of gram-positive and gram-negative bacterial infections and also for differentiating the...     

Spectroscopic investigation of the interaction of p-benzoquinone with casein in the solid state

The reaction between p-benzoquinone (PBQ) and casein (protein) in the solid state was studied. After reaction with protein, the FT-IR spectra showed a new band at 1215 cm^?1, with an intense sign attributed for casein/PBQ product. An optimum amount of PBQ for determination of the product when mixed with casein was 100 mg and a reaction time of 30 min. The product was stable for a period of 24 h after the reacting by heating. The interaction of PBQ with casein was investigated by FT-IR, reflectance, Raman and EPR spectroscopies. The reaction between PBQ and casein in the solid state yields a radical species (p-benzosemiquinone) that it is stabilized by the presence of p-biphenolate and p-benzoquinone species in the solid state.