A chromatography method for the screening and confirmatory detection of dexamethasone

Corticosteroids, such as dexamethasone, have been illegally used as growth promoting agents to obtain an economical benefit from increased muscle development. These substances remain in meat and other animal products and may have negative toxic consequences for consumers. A screening and confirmatory method for dexamethasone detection in feed and drinking water in livestock has been developed and validated. This method is based on immunoaffinity chromatography followed by reverse-phase high-performance liquid chromatrography (IAC–HPLC) with diode array detection (DAD) at 242 nm. Flumethasone was used as internal standard.

The method has been validated according to the European Union regulation 2002/657/EC for banned substances and, thus, the specificity, decision limit, detection capability, recovery and repeatability have been determined. The decision limits (CC) were 26 ng/mL for water and 190 ng/g for feed while detection capabilities (CCβ) were 30 ng/mL for water and 217 ng/g for feed. The method showed good accuracy and precision. The stability of dexamethasone under frozen storage has been studied over a 3.5-month period. No losses were observed, thus confirming that water samples taken by inspectors can be stored frozen for a few weeks until analysis. This method has proved to be relatively simple and useful for rapid screening and confirmation of the presence of dexamethasone in water and feed used for meat-producing animals.     

Biofuel and biomass from marine macroalgae waste

Nowadays, biofuel production of new raw materials has gained renewed interest. For that reason, the objective of this work is to use marine macroalgae for biodiesel and biomass production. The obtained results show that macroalgae are a suitable energy source for biodiesel production by direct transesterification, avoiding the previous step of oil extraction. It is an effective process because 95% of the oil is extracted. To analyze the optimum reaction conditions, the reaction was carried out at different amounts of methanol, catalyst concentrations, reaction temperatures, and reaction times. In addition, the macroalgae residue after transesterification was analyzed and it is suitable as fuel in biomass boilers.     

Advanced Subcompartmentalized Microreactors: Polymer Hydrogel Carriers Encapsulating Polymer Capsules and Liposomes

The design of compartmentalized carriers for advanced drug delivery systems or artificial cells and organelles is of interest for biomedical applications. Herein, a polymer carrier microreactor that contains two different classes of subcompartments, multilayered polymer capsules and liposomes, is presented. 50 nm‐diameter liposomes and 300 nm‐diameter polymer capsules are encapsulated into a larger polymer carrier capsule, demonstrating control over the spatial positioning of the subcompartments, which are either ‘membrane‐associated’ or 'free‐floating’ in the aqueous interior. Selective and spatially dependent degradation of the 300 nm‐diameter subcompartments (without destroying the structural integrity of the enzyme‐loaded liposomes) is also shown, by performing an encapsulated enzymatic reaction using the liposomal subcompartments. These findings cover several important aspects toward the development of engineered compartmentalized carrier vessels for the creation of artificial cell mimics or advanced therapeutic delivery systems.     

Innovations in value-addition of edible meat by-products

While muscle foods are the more commonly consumed portion of an animal, meat by-products such as the entrails and internal organs are also widely consumed. Considered high-priced delicacies or waste material to be tossed away, the use and value of offal-edible and inedible meat by-products depend entirely on the culture and country in question. The skin, blood, bones, meat trimmings, fatty tissues, horns, hoofs, feet, skull, and internal organs of harvested animals comprise a wide variety of products including human or pet food or processed materials in animal feed, fertilizer, or fuel. Industry is using science and innovation to add value to animal by-products far beyond its usual profitability. Regardless of the final product's destination, it is still necessary to employ the most up-to-date and effective tools to analyze these products for nutritional properties, to search for key active molecules in nutrition like bioactive peptides, food safety (antimicrobial peptides), medicine, cosmetics or other fields, to develop new technological applications and to continue innovation towards advanced value-addition of meat by-products.     

Release of multifunctional peptides by gastrointestinal digestion of sea cucumber (Isostichopus badionotus)

Sea cucumber is a benthic marine organism distributed worldwide and used as food in several Asian countries. The species Isostichopus badionotus is captured intensively off the Yucatan Peninsula, Mexico. Boiled I. badionotus was subjected to in vitro simulated gastrointestinal digestion using pepsin and a pepsin–Corolase PP^® mixture. ACE-inhibitory and radical scavenging activities, iron reducing capacity and cytotoxic effects against colorectal cancer cells were evaluated in the hydrolysates and their ultrafiltered fractions. ACE-inhibitory activity was potent in fractions containing peptides <3000 Da, an effect augmented with combined action of gastric (pepsin) and intestinal (Corolase PP^®) enzymes (IC₅₀ = 0.038 ± 0.004 mg/mL). Antioxidant activity was exerted by peptides with low and high molecular weights, depending on hydrolysis method. This is the first report of cytotoxic capacity against colorectal HT-29 cells in peptides from sea cucumber. Sea cucumber hydrolysates and ultrafiltered fractions are potential ingredients for development of functional foods.     

Comparative study of the physicochemical and palynological characteristics of honey from Melipona subnitida and Apis mellifera

Twenty‐four samples of Apis mellifera honey and twenty‐four samples of Melipona subnitida (Jandaira) honey were collected in the northeast of Brazil. Moisture, hydroxymethylfurfural, free acidity, insoluble solids in water, diastase activity, ashes, electrical conductivity, proteins, lipids, total carbohydrates, energy and sugars were the parameters analysed. The efficiency of the qualitative tests (Fiehe's test, Lugol's reaction, Lund's reaction) was tested. Pollen types and the corresponding plant species were identified in all samples (3 in Apis and 1 in Melipona). Apis mellifera honey samples demonstrated parameters in accordance with the Brazilian Legislation, while the Melipona subnitida honey samples displayed moisture (24.80%) and diastase activity (null) in discordance with the established by the regulation for Apis mellifera honeys. Apis honey samples presented higher values of electric conductivity (284.00 μS cm^?1) than the obtained from the Jandaira honey samples (102.77 μS cm^?1) as well as a darker colour (26.67 mmPfund) when compared with Jandaira honey (7.00 mmPfund). The concentration of the glucose, fructose and sucrose was higher in the Apis honeys than in the Jandaira honey. The characteristics of the two types of honey were very different, highlighting the need of developing specific legislation for stingless bees' honey.     

Structural and photoresponsive behavior of a series of (phenylene)azobenzene‐containing liquid‐crystalline methacrylic copolymers

A series of side‐chain liquid‐crystalline methacrylic copolymers, having various amounts of 4′‐(4‐decyloxyphenyl)‐4‐(hexyloxy)‐azobenzene as the mesogenic group, were synthesized and characterized by differential scanning calorimetry, polarizing optical microscopy and X‐ray diffraction to determine their mesomorphic properties, and by UV?visible spectrometry to elucidate their optical absorption characteristics. Also, birefringence and surface relief gratings were photoinduced in the films using a laser beam of 413 nm. Copolymers with high mesogen contents display a polymorphic behavior of the smectic type. The smectic order tends to disappear as the content of mesogens in the copolymer decreases, going from extended lamellar domains of chromophores packed in a parallel position, typical for smectic liquid crystals, to small aggregates of chromophores dispersed in an amorphous matrix. Important hypsochromic shifts (Δλ_max ≈ 20 nm), associated with π interactions between neighboring aromatic groups, confirm the aggregation of chromophores in lamellar structures. The light‐induced birefringence (0.005 ? 0.06) is not as high as expected but it corroborates that there exists a tight interplay between photoinduced orientation and intrinsic molecular order. Surface relief gratings were recorded in copolymers with low mesogen content (15 ? 30 mol%), showing by atomic force microscopy sinusoidal profiles with an average depth of around 150 nm. © 2013 Society of Chemical Industry     

Unconditional performance of the X¯ chart: Comparison among five standard deviation estimators

To design the $\overline{X}$ control chart, the in-control process mean and standard deviation must be estimated from historical samples, negatively affecting the chart's performance. The grand mean of a sample is the well-established estimator for the process mean. However, regarding the standard deviation, the chart's user has at least five different estimators available in the literature to choose from. In this paper, using intensive simulations, we study and compare the performance of the $\overline{X}$ chart (under normality assumption and three-sigma limits) among the most five used standard deviation estimators. The unconditional in-control run length (RL₀) is the most commonly used performance measure of a control chart, and many authors base their comparisons on the expectation of the RL₀ or on the mean square error of the estimators. In contrast, we based our comparison on the proportions of the RL₀ concentrated at some intervals that are usually considered undesired by the practitioner due to the high incidence of false alarms during the process monitoring (e.g., RL₀ between 1 and 200), occurring earlier than expected when compared with known parameter situations. From our results, all the studied standard deviation estimators generate similar performances. However, even with this similarity, we showed that one of the most recommended standard deviation estimators in the literature in control charts with estimated parameters may be the most inappropriate choice based on the undesired RL₀ proportions.     

When We Stop Talking Politics: The Maintenance and Closing of Conversation in Contentious Times

Despite the democratic significance of citizen talk about politics, the field of communication has not considered how that talk is weathering stresses facing our civic culture. We examine political talk during an archetypal case of political contentiousness: the recall of Governor Scott Walker of Wisconsin in 2012. Pairing qualitative and quantitative methods, we show that a fracturing of civic culture took place in which many citizens found it impossible to continue political discussion. Individuals at fault lines of contention, by nature of occupation, geographic location, or other personal circumstance, were most prone to this breakdown. Our results call into question the ability of talk to bridge political and social differences in periods of polarization and fragmentation, with implications for democratic functioning.     

Hyperprogressive Disease: Main Features and Key Controversies

Along with the positioning of immunotherapy as a preferential treatment for a wide variety of neoplasms, a new pattern of response consisting in a sudden acceleration of tumor growth has been described. This phenomenon has received the name of “hyperprogressive disease”, and several definitions have been proposed for its identification, most of them relying on radiological criteria. However, due to the fact that the cellular and molecular mechanisms have not been elucidated yet, there is still some debate regarding whether this fast progression is induced by immunotherapy or only reflects the natural course of some highly aggressive neoplasms. Moreover, contradictory results of trials including patients with different cancer types suggest that both the incidence, the associated factors and the implications regarding prognosis might differ depending on tumor histology. This article intends to review the main publications regarding this matter and critically approach the most controversial aspects.