Chewable Gelatin Emulsions for Oral Lipid Delivery: Elimination of Gastric Coalescence with κ-Carrageenan

Gelatin-based chewable emulsions can be a convenient vehicle for oral delivery of oils or lipid soluble bioactive components. Gelatin-stabilized emulsions do, however, rapidly flocculate and gradually coalesce in gastric fluids. This destabilization is caused by the combined action of pepsin and mucin and is most significant at pH 3, followed by pH 2, then pH 4. Through in vitro lipolysis experiments it is shown that this destabilization leads to a decrease in emulsion lipolysis rate after incubation in simulated gastric fluids (SGFs). In this paper a potential solution to this gastric instability is suggested: inclusion of 1 wt% sodium-κ-carrageenan (κ-CGN) of intermediate M_w into the gelatin emulsions. The κ-CGN used has minimal impact on gelatin gelled emulsion properties, preserving the soft elastic gelatin texture. When these gelled emulsions disintegrate in gastric fluids, electrostatic interactions between the gelatin and κ-CGN occur. While these interactions lead to heavy flocculation, they also protect the gelatin from pepsin action, providing full stability against emulsion coalescence during at least 2 h in SGF at pH 2–4. When the pH is neutralized upon mixing with intestinal fluids, the emulsion fully deflocculates and the rate of in vitro lipolysis is not affected by gastric residence time. Practical applications: Avoiding gastric coalescence in gelatin emulsions may lead to more reliable oral delivery of lipids or lipophilic components in gelatin-based chewable supplements or functional foods. Keeping the emulsion droplet size stable and small until reaching the intestine may lead to more rapid and efficient intestinal lipolysis, potentially advantageous in regards to bioavailability of slowly digested oils (e.g., omega-3 concentrate) or for people suffering from impaired lipid digestion. These findings may also be applicable to emulsion systems stabilized by other proteins.     

Tunable fluorescent and antimicrobial properties of poly(vinyl amine) affected by the acidic or basic hydrolysis of poly(N-vinylformamide)

Synthesis of poly(N-vinylformamide) (PNVF) and its subsequent hydrolysis to convert it to poly(vinyl amine) (PVAm) were performed. Kinetics of acidic and basic hydrolysis of poly(N-vinylformamide) (PNVF), and products of hydrolysis were investigated by using Fourier transform infrared, size exclusion chromatography, ¹H NMR, and ¹³C NMR spectroscopies, and thermogravimetric analysis. It was observed that amide groups did not completely transform into amine groups by acidic hydrolysis of PNVF while the conversion of amides into amine groups via basic hydrolysis of PNVF was complete in 12 h, as confirmed by spectroscopic measurements. Results of extensive characterization revealed significant structural and conformational differences between acidic and basic hydrolysis products. Fluorescence spectroscopy was used for the first time to follow the conversion of amide groups into amine groups. The fluorescence intensity of PVAm obtained from basic hydrolysis of PVNF showed significant increase with amide/amine conversion. Finally, PVAm obtained from acidic hydrolysis of PNVF demonstrated potent antimicrobial activity, 10–20 times more, against common pathogens for example, C. albicans as fungal strain and E. coli, S. aureus, B. subtilis, and P. aeruginosa as bacterial strains as compared to PVAm obtained from basic hydrolysis.     

CRISPR‐Based Technologies and the Future of Food Science

The on‐going CRISPR craze is focused on the use of Cas9‐based technologies for genome editing applications in eukaryotes, with high potential for translational medicine and next‐generation gene therapy. Nevertheless, CRISPR‐Cas systems actually provide adaptive immunity in bacteria, and have much promise for various applications in food bacteria that include high‐resolution typing of pathogens, vaccination of starter cultures against phages, and the genesis of programmable and specific antibiotics that can selectively modulate bacterial population composition. Indeed, the molecular machinery from these DNA‐encoded, RNA‐mediated, DNA‐targeting systems can be harnessed in native hosts, or repurposed in engineered systems for a plethora of applications that can be implemented in all organisms relevant to the food chain, including agricultural crops trait‐enhancement, livestock breeding, and fermentation‐based manufacturing, and for the genesis of next‐generation food products with enhanced quality and health‐promoting functionalities. CRISPR‐based applications are now poised to revolutionize many fields within food science, from farm to fork. In this review, we describe CRISPR‐Cas systems and highlight their potential for the development of enhanced foods.     

LWR pellet-cladding interactions: Materials solutions to SCC

Zirconium alloys are commonly used as fuel-cladding tubes in water reactors because of their inherent resistance to a variety of environmental conditions. One of the major fuel-reliability issues of the 1970s and early 1980s was pellet cladding interaction (PCI). The mechanism of PCI is one of stress corrosion cracking (SCC) by a combination of aggressive fission products and cladding stress from pellet expansion. The severity of the problem, in particular in boiling water reactors, led to the development of barrier cladding by co-extrusion of Zircaloy-2 with an inner iodide zirconium that essentially eliminated the PCI-related failures. However, the substantially lower corrosion resistance of the zirconium layer led to clad breach and failures by other mechanisms. The difference in corrosion resistance could lead to some dramatic differences in post-failure fuel operations. This article briefly summarizes how PCI-SCC factors led to the development of PCI-resistant fuel cladding and concludes with a note on future research needs. For more information, contact K.L. Murty, North Carolina State University, Department of Nuclear Engineering, Raleigh, NC 27695-7909 USA; (919) 515-3657; fax (919) 515-5115; e-mail murty@eos.ncsu.edu.     

Encapsulation of a proteolytically active novel bioproduct; controlling the release of proteinous components

Low trophic level organisms like zooplankton not only represent a valuable and unutilized source for marine proteins and lipids, but are also challenging with respect to high post-mortem protease activity. As an example, Ca–alginate encapsulated homogenized fresh zooplankton (Calanus finmarchicus) exhibited a high release of protein components when immersed in water due to diffusion of proteolytically degraded proteins. Initial diffusion rates at pH 7 increased with temperature up to 60 °C. Above 50 °C, the release was reduced because of protease instability after 12 h. The release of protein also increased with increasing ionic strength, most likely due to decreased electrostatic interaction between the alginate matrix and protein. As function of pH, the release of both amino groups as well as larger protein entities was apparently highest under alkaline conditions. Encapsulated heat-treated or alkali treated zooplankton had a high degree of release, the first 2 h reflecting the presence of osmoregulating amino acids as well as pre-digested proteins. After 2 h, no further release of protein was observed, which can be attributed to protease inactivation caused by these treatments. The present data show that all studied parameters (temperature, pH and ionic strength) have a profound impact on protein loss from the encapsulated model feed particles. Therefore, possible conservation methods to control the observed protein loss from marine raw materials in, e.g. marine feed formulations are suggested.     

The dynamics of death and meaning: The effects of death-relevant cognitions and personal need for structure on perceptions of meaning in life.

Do reminders of mortality increase or decrease perceptions of life’s meaning? The authors propose that death-relevant thought has divergent effects on meaning perceptions depending on individuals’ personal need for structure (PNS) or dispositional desire for structured knowledge. In prior research, high-PNS individuals primed with mortality-related stimuli were found to employ clearly structured conceptions of reality. Consequently, these individuals were expected to show stable or even bolstered perceptions of meaning when death thought was heightened. Low-PNS individuals did not show this tendency and were therefore expected to show decreased meaning under heightened death-thought activation. The results of Studies 1a–1d supported these hypotheses. Studies 2 and 3 sought to identify how low-PNS individuals might reaffirm meaning and found that death thought increased their willingness to explore novelty. Studies 4 and 5 directly tested the meaning-conferring function of novelty seeking among low-PNS individuals, showing that the consideration of novel interpretations of the world and their experiences affirmed a sense of meaning in life following reminders of death. Discussion focuses on the relationship between meaning and death and the unique ways low-PNS individuals respond to mortality concerns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical modeling of electrochemical–mechanical interactions in lithium polymer batteries

This paper presents a multi-scale finite element approach for lithium batteries to study electrochemical–mechanical interaction phenomena at macro- and micro-scales. The battery model consists of a lithium foil anode, a separator, and a porous cathode that includes solid active materials and a liquid electrolyte. We develop a multi-scale approach to analyze the surface kinetics and electrochemical–mechanical phenomena within a single spherical particle of the active material. Homogenization techniques relate parameters in the micro-scale particle model to those in the macro-scale model describing the lithium ion transport, electric potentials and mechanical response based on porous electrode theory.     

采用低成本射频器件实现医疗保健网络

由于医疗保健费用的持续上升,政府开始着力寻找新的、更有效的方法来预防和治疗疾病.为此本文提出了一个基于超低成本、低功耗的射频器件的解决方案.