The importance for food security of maintaining rust resistance in wheat

Wheat is one of the main sources of calories and protein of the world’s population and therefore the pathogens that cause rust diseases of the crop are a real threat to food security. Besides the continuous evolution of rust pathogens which repeatedly results in overcoming the resistance of commercial varieties throughout the world, plant breeders are also now challenged by the impacts of global climatic changes. Agricultural practices will need to keep pace with the intensification of sustainable food production in order to face the challenge of feeding a world population estimated to reach about nine billion by 2050. Contemporary wheat breeding has increasingly focused on the future, culminating in the emergence of a global partnership for breeding new wheat varieties with resistance to rust pathogens. Plant breeding now employs a wide range of both long-established and frontier technologies aimed at achieving the United Nations Millennium Development Goals of ending hunger and extreme poverty (MDG1), while concurrently promoting environmental sustainability (MDG7) through global partnerships for development (MDG8).     

Shelf Life of Pretreated Dried Tomato

Determining the shelf life has become a factor of major importance in the development of foods designed to meet consumer demands in terms of quality and safety. The goal of the present study was to investigate the shelf life of vacuum-packed dried tomatoes, stored at both room and refrigeration temperature (4 °C) for a period of 180 days. The following determinations were performed during the storage period studied: microbiological analysis, instrumental color, lycopene, and ascorbic acid. Sorption isotherms were determined at both temperatures (room temperature and 4 °C). The microbiological quality of vacuum-packed dried tomatoes remained unchanged during 180 days for the refrigerated samples and 90 days for the samples stored at room temperature. The rate constant (k) of lycopene degradation of the refrigerated samples and the samples stored at room temperature was 3.209 × 10⁻⁵ and 12.994 × 10⁻⁵/day, respectively. The rate constant (k) of ascorbic acid degradation was 3.339 × 10⁻⁴/day for cold storage and 76.655 × 10⁻⁴/day for storage at room temperature. The tomatoes stored at room temperature were subjected to analysis over 90 days of storage, period after which both the appearance and sensory characteristics of the product fell below the levels of consumer acceptability. As for the tomatoes stored at refrigeration temperature, the original sensory characteristics were maintained throughout the entire storage period of 180 days.     

Four modified sodium alginate/carboxymethylcellulose blends for prednisone delivery

Polysaccharides have been widely used for the development of drug delivery systems. These systems can be physicochemically modified to enhance their stabilities and control their drug release profiles. However, such modifications cannot alter their biocompatibility or toxicity. Herein, four structurally modified sodium alginate/carboxymethylcellulose blends are synthesized and loaded with prednisone, and the effects of the modifications on their hydrolytic degradation rates, biocompatibilities, toxicities, and drug release profiles are investigated. All the blends are ionically cross-linked with Ca²⁺ and Fe³⁺. Blend 1 is not modified further, blend 2 is additionally reinforced with 8% w/w of cellulose nanocrystals, blend 3 is treated with epoxidized linseed oil to develop a hydrophobic layer, and blend 4 is chemically cross-linked with epichlorohydrin. Blends 2 and 4 exhibit similar physicochemical characteristics, appropriate hydrolytic degradation rates and drug release patterns, as well as biocompatibility and non-toxicity. In-vitro studies using the osteoblasts and CAM assay demonstrate that blends 2 and 4 are also biocompatible and non-toxic. In contrast, blend 1 exhibits the highest drug release rate, followed by blend 3.     

Elements concentration analysis in groundwater from the North Serra Geral aquifer in Santa Helena-Brazil using SR-TXRF spectrometer

In this work the analysis of elements concentration in groundwater was performed using the synchrotron radiation total-reflection X-ray fluorescence (SR-TXRF) technique. A set of nine tube-wells with serious risk of contamination was chosen to monitor the mean concentration of elements in groundwater from the North Serra Geral aquifer in Santa Helena, Brazil, during 1 year. Element concentrations were determined applying a SR-TXRF methodology. The accuracy of SR-TXRF technique was validated by analysis of a certified reference material. As the groundwater composition in the North Serra Geral aquifer showed heterogeneity in the spatial distribution of eight major elements, a hierarchical clustering to the data was performed. By a similarity in their compositions, two of the nine wells were grouped in a first cluster, while the other seven were grouped in a second cluster. Calcium was the major element in all wells, with higher Ca concentration in the second cluster than in the first cluster. However, concentrations of Ti, V, Cr in the first cluster are slightly higher than those in the second cluster. The findings of this study within a monitoring program of tube-wells could provide a useful assessment of controls over groundwater composition and support management at regional level.     

Selective Laser Melting of Maraging Steels Using Recycled Powders: A Comprehensive Microstructural and Mechanical Investigation

Selective laser melting (SLM) is an additive manufacturing (AM) technique designed to use a high energy density laser to fuse metallic powders for producing three-dimensional parts. So far, most studies of SLM have been focused on using virgin metal powders. There are few comprehensive studies on the microstructure and mechanical properties of SLM-produced parts using recycled powders, especially for maraging steels. In this study, we employ recycled steel powder (reused after 113 building cycles) in the SLM process to print multiple shaped components and systematically characterize the microstructure and mechanical properties (indentation, tensile, and Charpy testing). Our results show that maraging steel produced with recycled powder exhibit the nearly identical microstructure and mechanical properties (940 MPa yield strength, 1127 MPa ultimate tensile strength, 11 pct elongation, and 47.5 J room temperature impact fracture energy) to those produced using virgin powders. This study provides a useful generic guide towards using recycled metal powders in the SLM processing, promoting an economic solution to industrial productions.

     

The impact of focused degree projects in chemical engineering education on students’ research performance,retention, and efficacy

Recent reforms in engineering education have emerged to meet the changing needs of engineers, however sparse research exists that comprehensively assesses the outcomes associated with such engineering education efforts. Accordingly, there is an urgent need for educational approaches tied to assessing engineering students’ performance, retention, and impact.This study's purpose is to explore the relationship between sequential chemical engineering degree projects and students’ performance, engineering efficacy, multidisciplinarity, and retention. The projects for this education for chemical engineers research are thematically focused laboratory experiments embedded in a four-year chemical engineering program. Each project component is connected to the next, is increasingly complex as courses advanced, and is aligned with essential course content. This connectivity enables students to participate in logically sequenced experiments that culminate in well-developed senior laboratory projects. This study's educational impact was determined via comparison between seniors’ and freshmen’ performance, efficacy and retention.Results of this research indicate that the use of degree projects in chemical engineering education is impactful, resulting in students’ increased understanding of experimentation and course content; meaningful, resulting in statistically significant increased student chemical engineering efficacy; and engaging, resulting in students’ satisfaction with program impact, engagement with peers during experimentation, and dramatically increased student retention.     

Characterization of Carnauba Wax Inorganic Content

In this work the analysis of inorganic elements (Al, Ca, Cu, Fe, K, Mg, Mn, Na and Zn) in different types of carnauba waxes (types 1, 3 and 4) was implemented. The Box‐Behnken experimental design was used to optimize the digestion of the carnauba wax sample using a microwave‐assisted approach. The following parameters were evaluated: microwave power applied (600–1,000 W), time of microwave power application (5–20 min) and nitric acid volume (1–4 mL). The residual carbon content (%RCC) was measured by ICP OES (inductively coupled plasma optical emission spectrometry) to evaluate the efficiency of the digestion. The %RCC values in all of the experiments were below 16 %. The best conditions for carnauba wax digestion were found: 800 W applied power for 15 min using 2.5 mL of HNO₃. In these conditions the %RCC was lower than 4 %. The amounts of Al, Ca, Cu, Fe, K, Mg, Mn, Na and Zn in these samples were determined by ICP OES. The average contents of Al, Ca, Fe and K found in the carnauba wax type 1 were 28.6 ± 1.5, 33.8 ± 2.8, 18.5 ± 1.1 and 37.2 ± 2.5 mg kg^?1, respectively. For carnauba wax types 3 and 4 larger amounts were found. The principal components analysis (PCA) showed three groups of carnauba wax with the first two principal components.     

Estimates of the theoretical maximum daily intake of phenolic antioxidants BHA, BHT and TBHQ in Brazil

The theoretical maximum daily intakes (TMDI) of the phenolic antioxidants butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tertbutyl hydroquinone (TBHQ) in Brazil were estimated using food consumption data derived from a household economic survey and a packaged goods market survey. The estimates were based on maximum levels of use of the food additives specified in national food standards. The calculated intakes of the three additives for the mean consumer were below the ADIs. Estimates of TMDI for BHA, BHT and TBHQ ranged from 0.09 to 0.15, 0.05 to 0.10 and 0.07 to 0.12mg/kg of body weight, respectively. To check if the additives are actually used at their maximum authorized levels, analytical determinations of these compounds in selected food categories were carried out using HPLC with UV detection. BHT and TBHQ concentrations in foodstuffs considered to be representive sources of these antioxidants in the diet were below the respective maximum permitted levels. BHA was not detected in any of the analysed samples. Based on the maximal approach and on the analytical data, it is unlikely that the current ADI of BHA (0.5mg/kg body weight), BHT (0.3mg/kg body weight) and TBHQ (0.7mg/kg body weight) will be exceeded in practice by the average Brazilian consumer.