Comparison between photocatalytic ozonation and other oxidation processes for the removal of phenols from water

Photocatalytic ozonation (1O₃ + VUV + TiO₂), ozonation (O₃), catalytic ozonation (O₃ + TiO₂), ozone photolysis (O₃ + VUV), photocatalysis (TiO₂ + VUV) and photolysis (VUV) have been compared in terms of formation of intermediates, extent of, mineralization (TOC, COD, chloride, nitrate) and kinetics in the aqueous treatment of three phenols (phenol, p‐chlorophenol and p‐nitrophenol). In all cases, photocatalytic ozonation led to lower degradation times for chemical oxygen demand and total organic carbon removal. Intermediates formed were similar in the different oxidation systems with some exceptions. They can be classified into three different types: polyphenols (resorcinol, catechol, hydroquinone), unsaturated carboxylic acids (maleic and fumaric acids) and saturated carboxylic acids (glyoxylic, formic and oxalic acids). First order kinetic equations have been checked for the oxidation processes studied in the case of the parent compound. Rate constants of these systems have also been calculated. Copyright © 2005 Society of Chemical Industry     

Proliferation to Apoptosis Tumor Cell Ratio as a Biomarker to Improve Clinical Management of Pre-Malignant and Symptomatic Plasma Cell Neoplasms

Proliferation and apoptosis of neoplastic cells are prognostic biomarkers in plasma cell neoplasms (PCNs). The prognostic capacity of proliferation to apoptosis ratio (Ratio-PA) in the era of immunomodulatory treatments is re-evaluated in 316 gammopathy of undetermined significance (MGUS), 57 smoldering multiple myeloma (SMM), and 266 multiple myeloma (MM) patients. Ratio-PA of 0.77 ± 0.12, 1.94 ± 0.52, and 11.2 ± 0.7 (p < 0.0001) were observed in MGUS, SMM, and MM patients. Ten-year overall survival (10y-OS) rates for patients with low/high Ratio-PA were 93.5%/77.3% p < 0.0001) for MGUS, 82.5%/64.7% (p < 0.05) for SMM, and 62.3%/47.0% (p < 0.05) for MM. For patients with low, intermediate, and high risk, 10y-OS for low/high Ratio-PA were 95.5%/72.9% (p < 0.0001), 74.2%/50.4% (p < 0.0001), and 35.3%/20.0% (p = 0.836), respectively. Ratio-PA was an independent prognostic factor for OS (HR = 2.119, p < 0.0001, Harrell-C-statistic = 0.7440 ± 0.0194) when co-analyzed with sex, age, and standard risk. In patients with Ratio-PA^high, only first-line therapy with VRd/VTd, but not PAD/VCD, coupled with ASCT was associated with high 10y-OS (82.7%). Tumor cell Ratio-PA estimated at diagnosis offers a prognostic biomarker that complements standard risk stratification and helps to guide the clinical management of pre-malignant and symptomatic PCNs. Every effort should be made to provide first-line therapies including VTd or VRd associated with ASCT to patients with Ratio-PA^high at higher risk of progression and death.     

Homogeneous Catalyzed Ozone Decomposition in the Presence of Co(II).

The homogeneous decomposition of ozone in the presence of a Co(II) catalyst has been investigated in aqueous solution. Under the conditions investigated (Co(II) concentration: 0.0 – 2.0?ppm, pH: 1.6- 8.4, O₃ concentration: 5 10^?5 – 2.0 10⁴?M) the process can be assumed to follow pseudo first order kinetics with respect to ozone. Cobalt concentration dependency also obeys first order kinetics although it may be considered to reach a steady state concentration. pH exerts a positive influence on the decomposition rate from 1.6 to 7.1, the process leveling off at pH 8.4. An Arrhenius analysis of the temperature effect gave a moderate activation energy of the global reaction (E=10917?cal mol^?1). A more detailed radical mechanism than a simple pseudo first order reaction can be postulated for simulation purposes. By numerical optimization of some unknown kinetic constants the influence of several operating variables can be adequately predicted.     

Human infection with Hymenolepis diminuta: case report from Spain

We report a case of Hymenolepis diminuta infection in a human. The patient was a 5-year-old girl referred to us through the onset of a cyanotic attack. Treatment with a single dose (10 mg/kg of body weight) of praziquantel was ineffective, but the parasite was eradicated after three treatment cycles with the same drug at dosages of 25 mg/kg/day for 5 days.     

Treatment of brines by combined Fenton's reagent-aerobic biodegradation. II. Process modelling

Process modelling of the integrated Fenton's reagent-aerobic biodegradation system has been carried out by considering a detailed reaction mechanism for the chemical oxidation step and the generalised Monod equation for the biological treatment. Chemical oxygen demand has been contemplated as a pseudo-component for simulation purposes. The proposed mechanism takes into consideration different features experimentally found. Thus, the inefficient hydrogen peroxide decomposition into oxygen and water, the influence of temperature and other operating variables and the role of oxygen have been considered. The aerobic biodegradation of the effluent after the chemical oxidation has taken place has been well simulated by Monod equation with no inhibitory terms. Dependency on temperature has been correlated by Arrhenius expression.     

Identification of burnt areas in Mediterranean forest environments from ERS-2 SAR time series

This article presents the multitemporal analysis of a Synthetic Aperture Radar (SAR) image series of an area affected by several fires during the years 2000 and 2001 in Central Portugal. An initial study was carried out to determine the best conditions to acquire optimal SAR imagery. Burnt areas were classified using neural network techniques. The neural network classification presented an overall accuracy of 92.11% using an entire European Remote Sensing (ERS) SAR time series, whereas an accuracy of 89.90% was achieved when using a subset of scenes selected through principal components analysis (PCA). Finally, the burnt area maps obtained were compared to estimates from the Portuguese Forest Services (DGF, Direc@@o Geral das Florestas) and the European Forest Fires Damage Assessment System (EFFDAS). This comparison showed that the SAR-based methodology provided higher accuracy than the other systems. The sensitivity of the SAR data to determine burnt severity allowed the discrimination of partially burnt areas and isles within the perimeter of the fire. These results show that the analysis of the temporal variation in the ERS-SAR backscatter coefficient permits the extraction of accurate and reliable information on the position and extent of burnt areas in Mediterranean forest environments.     

Curriculum deregulating practices: towards the loss of educational sense

In this article, the author analyses the implications of three main deregulating practices that sometimes work towards contradictory developments in the processes of contemporary educational reforms. First, the progress towards a more decentralisating school system and the increasing school's autonomy with bureaucratic interventionism of the administration. Secondly, the loss of the unique and coherent curriculum as a consequence of the growing cultural differentiation, which approaches us to certain relativism, questioning the monoculturalism of educational content. This could result in considering difference more valuable than equality. Thirdly, changes in teachers' labour. These are forces and motivations that, together, produce some initiatives and experiences not always easily assessed. The consequences of these tendencies result in contradictory demands of change in the school culture, that need to be reviewed.     

Full-Wave Modal Analysis of Slow-Wave Periodic Structures Loaded With Elliptical Waveguides

In this paper, a novel full-wave method for the modal characterization of periodic structures loaded with elliptical waveguides is presented. This method relies on an integral equation formulation solved via the method of moments, which finally leads to the solution of a standard eigenvalue problem. The required modal spectrum of elliptical waveguides is determined through the boundary integral-resonant mode expansion technique. For validation purposes, the proposed analysis method is first successfully applied to periodic waveguide structures already considered in the technical literature. Then, our new algorithm is used to compute the related Brillouin diagrams and the interaction impedance of new periodic structures loaded with elliptical waveguides. Not only the main interacting mode (such as the $TM_{01}$ mode) is studied, but higher-order Floquet modes are also considered. These results have potential applications as slow-wave structures for high-power microwave devices and possibly filtering structures at millimeter-wave frequencies.      

Lessening polygalacturonase activity in a commercial enzyme preparation by exposure to pulsed electric fields

The effect of high-intensity pulsed electric field (HIPEF) treatments on polygalacturonase (PG) activity in an aqueous solution of a commercial enzyme preparation was evaluated. HIPEF treatments reduced PG activity notably. Exponentially decaying pulses of 40 and 160 µs generated by a laboratory scale device were applied in a batch processing and bipolar mode. Electric fields ranged from 5.18 to 19.39 kV/cm. The number of pulses ranged up to 400. Temperature was always below 25 °C. Maximum inactivation of PG activity (98%) required 32.4 ms HIPEF treatment at 10.28 kV/cm. PG activity depleted exponentially because of HIPEF treatments. The first order rate constants ranged from 32 to 590 µs ^-1 and increased exponentially with electric field intensity. PG activity decreased exponentially with input electric energy density.