A practical demonstration of water disinfection using TiO2 films and sunlight

The scope of this study is the assessment of the efficiency of solar disinfection by heterogeneous photocatalysis with sol-gel immobilized (titanium dioxide) TiO2 films over glass cylinders. The solar disinfection process known as SODIS was considered as a reference. Spring water naturally polluted with coliform bacteria was exposed to sunlight in plastic bottles with and without TiO2 over simple solar collectors and the disinfection effectiveness was measured. Total and fecal coliforms quantification was performed by means of the chromogenic substrate method in order to obtain the efficiency of each disinfection treatment. The disinfection with TiO2 was more efficient than the SODIS process, inactivating total coliforms as well as fecal coliforms. On a sunny day (more than 1000 W m(-2) irradiance), it took the disinfection with immobilized TiO2 15 min of irradiation to inactivate the fecal coliforms to make them undetectable. For inactivation of total coliforms, 30 min was required, so that in less than half the time it takes SODIS, the treated water complies with the microbial standards for drinking water in Mexico. Another important part of this study has been to determine the bacterial regrowth in water after the disinfection processes were tested. After SODIS, bacterial regrowth of coliforms was observed. In contrast, when using the TiO2 catalyst, coliforms regrowth was not detected, neither for total nor for fecal coliforms. The disinfection process using TiO2 kept treated water free of coliforms at least for seven days after sun irradiation. This demonstration opens the possibility of application of this simple method in rural areas of developing countries.     

Sustainable ethanol production from lignocellulosic biomass - Application of exergy analysis

The sustainability of the second-generation biofuels requests to confirm that the energy produced from lignocellulosic biomass is significantly greater than the energy consumed in the process. As lignocellulosic biomass does not affect the food supply, sugarcane bagasse was analyzed as a raw material for second-generation biofuels production. Exergy analysis serves as a unified and effective tool to evaluate the global process efficiency. Exergy analysis evaluates the performance of sugarcane bagasse and its sustainability in the bioethanol production process. In this work, four ethanol production topologies using the typical daily amount of residual biomass produced by the sugar industry were compared. The exergy analysis concept is effective in screening design alternatives with the lowest environmental impact for second-generation bioethanol fuel production from renewable resources. This study was executed by the use of the Aspen Plus^® program and other software developed by the authors.     

Detection of roe deer,red deer,and hare meat in raw materials and processed products available in Poland

To allow detection of meat from the most popular game species in Poland, we developed a PCR-based method for identification of roe deer (Capreolus capreolus), red deer (Cervus elaphus), and hare (Lepus europaeus). The designed primers were based on the noncoding, mitochondrial D-loop region. Amplicon sizes ranged from 116 to 255 bp. The primers exhibited no cross-reactivity with the DNA from common slaughter and other game species. The detection limit of the assay was established to be below 0.001 % in raw red deer (C. elaphus) and hare (L. europaeus) meat, and below 0.01 % in raw roe deer (C. capreolus) meat, whereas <0.5 % of hare and red deer meat in processed samples could be detected. The PCR-based assay was used for authentication of 17 samples of raw game meat and 32 samples of game meat-containing products available in Polish markets. Analysis of all tested raw meat and processed products revealed the presence of DNA of investigated species in concordance with producers’ declarations.     

Software diversity: state of the art and perspectives

Diversity is prevalent in modern software systems to facilitate adapting the software to customer requirements or the execution environment. Diversity has an impact on all phases of the software development process. Appropriate means and organizational structures are required to deal with the additional complexity introduced by software variability. This introductory article to the special section “Software Diversity—Modeling, Analysis and Evolution” provides an overview of the current state of the art in diverse systems development and discusses challenges and potential solutions. The article covers requirements analysis, design, implementation, verification and validation, maintenance and evolution as well as organizational aspects. It also provides an overview of the articles which are part of this special section and addresses particular issues of diverse systems development.     

Exploring the immunoproteome for ovarian cancer biomarker discovery

Most scientific efforts towards early detection of ovarian cancer are commonly focused on the discovery of tumour-associated antigens (TAA). Autologous antibodies against TAA, however, may serve as more sensitive diagnostic markers. They circulate in the blood before TAA and are usually more abundant than the TAAs themselves as a result of amplification through the humoral immune response. Accumulating evidence also suggests that a humoral response already exists during malignant transformation when aberrant gene expression is translated into premalignant cellular changes. This article reviews the current knowledge about autoantibodies against TAA in ovarian cancer and presents current immunoproteomic approaches for their detection.     

Effects of sodium citrate plus sodium diacetate and buffered vinegar on Escherichia coli O157:H7 and psychrotrophic bacteria in brine-injected beef

The objective of this research was to examine the effects of sodium citrate plus sodium diacetate or buffered vinegar on Escherichia coli O157:H7 and psychrotrophic bacteria when incorporated in brine solutions for injected beef. Two experiments were conducted in which 30 top rounds and 30 top sirloins were injected (110%) to contain (i) 0.5% sodium chloride and 0.4% sodium tripolyphosphate as the control (CNT); (ii) CNT with a 1% solution of 80% sodium citrate plus 20% sodium diacetate (SC + D); or (iii) CNT with 2% buffered vinegar (VIN) in the final product. For the E. coli challenge, muscles were surface inoculated to target 6 log CFU/cm(2). After injection and 10 days of storage in a vacuum package (4°C), one half of each muscle was sampled raw and the other half was cooked to an internal temperature of 60°C with a 12-min hold. For raw samples, a significant reduction of 0.6 and 1.0 log CFU/g of E. coli O157:H7 was observed in both SC + D- and VIN-injected top rounds and sirloins, respectively. All cooked samples were E. coli O157:H7 negative. For psychrotrophic analysis, subprimals were injected and vacuum packaged for 10 days at 0 ± 1°C. After 10 days of storage, steaks were fabricated and placed in aerobic display (4 ± 1°C) for 1, 7, 14, and 21 days. Psychrotrophic organism growth was restricted in SC + D and VIN samples when compared with CNT on all days except day 1. Sodium citrate plus sodium diacetate or buffered vinegar may improve the safety and shelf life of multineedle brine-injected beef.     

Roles of singlet oxygen and triplet excited state of dissolved organic matter formed by different organic matters in bacteriophage MS2 inactivation

Inactivation of bacteriophage MS2 by reactive oxygen species (ROS) and triplet excited state of dissolved organic matter (³DOM*) produced by irradiation of natural and synthetic sensitizers with simulated sunlight of wavelengths greater than 320 nm was investigated. Natural sensitizers included purified DOM isolates obtained from wastewater and river waters, and water samples collected from Singapore River, Stamford Canal, and Marina Bay Reservoir in Singapore. Linear correlations were found between MS2 inactivation rate constants (k_obs) and the photo-induced reaction rate constants of 2,4,6-trimethylphenol (TMP), a probe compound shown to react mainly with ³DOM*. Linear correlations between MS2 k_obs and singlet oxygen (¹O₂) concentrations were also found for both purified DOM isolates and natural water samples. These correlations, along with data from quenching experiments and experiments with synthetic sensitizers, Rose Bengal (RB), 3′-methoxyacetophenone (3′-MAP), and nitrite (₂NO⁻)$\left({{\text{NO}}_2}^{-}\right)$, suggest that ¹O₂, ³DOM*, and hydroxyl radicals (^•OH) could inactivate bacteriophage MS2. Linear correlations between MS2 k_obs and Specific Ultraviolet Absorption determined at 254 nm (SUVA₂₅₄) were also found for both purified DOM isolates and natural samples. These results suggest the potential use of TMP as a chemical probe and SUVA₂₅₄ as an indicator for virus inactivation in natural and purified DOM water samples.     

Metabolic parameters and risk factors associated with abdominal obesity among female adolescents in public schools in the Distrito Federal (Brazil)

This study aimed to estimate the prevalence of abdominal obesity and investigate their association with parameters markers of metabolic syndrome (MS) and its risk factors in female adolescents. It is a cross-sectional study with 150 adolescents from 10 public schools in the Federal District, Brazil. The presence of abdominal obesity was considered by measuring waist circumference above the 80th percentile, according to Taylor et al. (2000). The associated factors included sociodemographic characteristics, health status of adolescents and their parents, physical activity, eating habits, blood pressure and biochemical profile. The abdominal obesity prevalence ratio (PR) was estimated by Poisson regression model, with 95% CI. Among the adolescents studied (age= 15.6 +/- 0.8 years; BMI = 21.0 +/- 3.0 kg/m2), prevalence of abdominal obesity was 20%, and this condition was not associated with sociodemographic variables, physical activity and diet. However, abdominal obesity was significantly associated with intake of less than 4 meals a day (PR = 2.27; IC95% 1.27-4.10), previous obesity (PR = 2.36; IC95% 1.31-4.01), history of parental chronic disease (PR = 3.55; IC 95% 1.63-7.75), fasting insulin = 15 uUi/mL (PR = 3.05; IC 95% 1.36-6.82) e HDL-c > 40 mg/dL (PR = 0.39; IC95% 0.23-0.67). In this population, modifiable factors, family history and determinants of MS, such as insulin and HDL-c were associated with abdominal obesity, which points to the need for effective health promotion among adolescents.