Calcite Prisms from Mollusk Shells (Atrina Rigida): Swiss‐cheese‐like Organic–Inorganic Single‐crystal Composites

Biogenic single‐crystal composites, such as sea urchin spines and calcitic prisms from mollusk shells, contain organic macromolecules inside of inorganic single‐crystal matrices. The nanoscale internal structure of these materials, however, is poorly understood, especially how the biomacromolecules are distributed within the crystals without significantly disrupting the crystalline lattice. Here, annular dark‐field scanning transmission electron microscopy and electron tomography reveal, in three dimensions, how biomacromolecules are distributed within the calcitic prisms from Atrina rigida shells. Disk‐like nanopatches, whose scattering intensity is consistent with organic inclusions, are observed to be anisotropically arranged within a continuous, single‐crystalline calcite matrix. These nanopatches are preferentially aligned with the (000l) planes of calcite. Along the crystallographic c‐axis, there are alternating organic‐rich and ‐poor regions on a length scale of tens of nanometers, while, in the ab plane, the distribution of nanopatches is more random and uniform. The structural features elucidated in this work have relevance to understanding the structure–property relationships and formation mechanisms of biominerals, as well as to the development of bio‐inspired strategies to extrinsically tune the properties of single‐crystals.     

Carbon Nanotubes: Biocompatibility of Immobilized Aligned Carbon Nanotubes (Small 8/2011)

In vivo host responses to an electrode‐like array of aligned carbon nanotubes (ACNTs) embedded within a biopolymer sheet are reported. This biocompatibility study assesses the suitability of immobilized carbon nanotubes for bionic devices. Inflammatory responses and foreign‐body histiocytic reactions are not substantially elevated when compared to negative controls following 12 weeks implantation. A fibrous capsule isolates the implanted ACNTs from the surrounding muscle tissue. Filamentous nanotube fragments are engulfed by macrophages, and globular debris is incorporated into the fibrous capsule with no further reaction. Scattered leukocytes are observed, adherent to the ACNT surface. These data indicate that there is a minimal local foreign‐body response to immobilized ACNTs, that detached fragments are phagocytosed into an inert material, and that ACNTs do not attract high levels of surface fouling. Collectively, these results suggest that immobilized nanotube structures should be considered for further investigation as bionic components.     

Racial microaggressions and worldviews.

Comments by on an article entitled "Racial microaggression? How do you know?" by Rafael S. Harris Jr. (see record2008-05553-011). The author states that in our original article we asserted that the racial reality of POC was generally different from the racial reality of White Americans and that often times interpretations of situations and events are the result of worldviews or racial identity. When references are made to POC, or to “visible racial/ethnic groups,” reference is being made not only to the shared cultural characteristics, norms, values, and attitudes of the group (African American, Asian American, American Indian, and Latino/Hispanic American) but to a self-designation of racial identity formed from sociopolitical experiences of unequal social, economic, legal, and political power in U.S. society that are based on visible racial characteristics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developement of neutral polymeric bonding agents for propellants with polar composites filled with organic nitramine crystals

Versatile neutral polymeric bonding agents (NBPA's) have been developed for energetic propellants in which polar HMX particles are dispersed in a polar binder matrix containing highly polar plasticizers (TMETN, NG, etc.). Using a semi-empirical approach through adjustment of solubility parameters and molecular weight, neutral acrylonitrile interpolymers were synthesized which mix uniformly with the submix and still have a high affinity for the HMX particles when they are added. Addition of about 0.2 % w/w of NPBA to HMX-filled PEG binders increases the strength by a factor of as high as five compared to samples with no NPBA, and also eliminates the sudden decrease in modulus (knee) which occurs at relatively low elongation. The degree of filler reinforcement achieved by our NPBA's in energetic propellants is far superior to that achieved by adding nitrocellulose or any other previously proposed bonding agents, and similar to the effect of precoating the HMX particles with polyurea shells.     

Characterization of the Arcobacter contamination on Belgian pork carcasses and raw retail pork

In the present study, the occurrence of Arcobacter was assessed at four sites on 169 porcine carcasses (foreleg, chest, pelvis and ham) at different stages of slaughter and 47 pork products at retail. Carcass swab samples were enriched in Arcobacter broth containing 5-fluorouracil, amphotericine B, cefoperazone, novobiocine and trimethoprim as selective supplement. After microaerobic incubation, arcobacters were isolated using Arcobacter selective agar plates, containing the selective supplement described above. Some carcass samples and all pork samples were also examined quantitatively. All 862 isolates were identified by a species-specific m-PCR-assay and 182 isolates were further characterized by ERIC-PCR. Arcobacters were isolated from one or more sampling places on 96.4% of the carcasses, with the foreleg and the chest area as the two most contaminated sites. Furthermore, A. cryaerophilus was the most common species. Chilling decreased the number of positive carcasses, but did not eliminate all arcobacters. Direct isolation revealed that only a few carcasses were contaminated with arcobacters on foreleg and/or chest at levels higher than 10(2 )cfu/100 cm(2). Characterization demonstrated a large heterogeneity among the isolates, with ten genotypes present on more then one site per carcass. Fourteen genotypes were simultaneously present on carcasses from different herds slaughtered on the same day, which may indicate cross-contamination. Arcobacters were present in 21% of the pork samples taken at retail, but contamination levels did not exceed 100 cfu per gram. Characterization of the A. butzleri and A. cryaerophilus isolates indicated an additional contamination during processing at retail.     

Dietary intakes of some essential and non-essential trace elements, nitrate, nitrite and N-nitrosamines, by Dutch adults: estimated via a 24-hour duplicate portion study

Duplicate portions of 24-hour diets of 110 adults have been analyzed for aluminium, cadmium, copper, lead, manganese, mercury, zinc, nitrate, nitrite and volatile N-nitrosamines. The mean daily intake of copper (1.2 mg) is only about 50% of recommended values; mean daily intakes for manganese (3.3 mg) and zinc (8.4 mg) are adequate and marginal respectively with respect to recommended amounts. For the non-essential elements Al, Cd, Hg and Pb, mean daily intakes of 3.1 mg, 0.01 mg, 0.002 mg and 0.034 mg were found, respectively. For Cd this amounts to 17% of the acceptable daily amount, for Al, Hg and Pb 5%, 5% and 8%, respectively. Since 1976-1978 the dietary intake of lead has been reduced by a factor three; for the other six elements daily dietary intakes are almost the same as in 1976-1978. Average nitrate intake was 52 mg NO3-/day, about 25% of the ADI. Only 16 diets contained a measurable amount of nitrite. The highest daily intake (0.7 mg NO2-) is less than 10% of the ADI. Volatile N-nitrosamines were detectable in two duplicate diets (NDMA and NPIP). It is estimated that the daily dietary intake of volatile N-nitrosamines is around 0.1 microgram or less.     

Local Notions of Healthy Eating and National Dietary Guidelines: A Comparison in Vulnerable Salvadoran Communities

This study presents an assessment of local definitions and perceptions concerning healthy eating through a study in four resource-poor border communities in El Salvador. The study included focus groups, key-informant interviews, and observations of the food environment. Local definitions of healthy eating elicited through focus groups were compared to the national Salvadoran dietary guidelines recommendations. The comparison revealed several areas of overlap (including the importance of dietary variety, fruits, and vegetables, among others) and omissions (mention of limiting sweets/candy, salt, sugar, and alcohol). Focus group participants expressed concerns over the origin of their foods and whether food contained harmful chemicals. These conversations also revealed the contradictions between nutrition knowledge and preferences for foods classified as unhealthy. This article concludes with a discussion about barriers to healthy eating identified in the focus groups and through the food environment assessment.     

Differentiated Patterns of Legume Sensitisation in Peanut-Allergic Patients

Patients with peanut allergy are often serologically sensitised to other legumes. If primary peanut allergy was contracted, secondary allergies to other legume plants may develop. The cross-sensitisation implies an enhanced risk of food-related anaphylaxis for the patients even if its clinical relevance is under discussion. In the present study, 32 patients with anti-peanut immunoglobulin E-levels (IgE) of at least class 1 according to the ImmunoCap™ classification system were included. The patients had been referred to the Norwegian National Register and Reporting System for Severe Allergic Reactions to Food with histories of anaphylaxis by the consumption of legume-containing foods. The patient sera were analysed for IgE that reacted to peanut (Arachis hypogea), soybean (Glycine max), pea (Pisum sativum), lupin (Lupinus albus) and fenugreek (Trigonella foenum graecum). Immunoblot experiments were performed using extracts of in total eight different legume plants. IgE measurements and blot analyses revealed differentiated patterns of legume sensitisation. One third of the patients had anti-peanut IgE class 4 to 6. In contrast, just one patient had specific IgE higher than class 4 to respectively pea, soybean and fenugreek. However, ten patients had elevated anti-fenugreek IgE (≥class 3), significantly more than for the other legumes. The second highest levels were found for soybean, followed by pea and lupin. The immunoblots showed particularly strong IgE binding to proteins at 12, 22, 30, 36 and 50 kDa for all legumes, indicating that the major peanut allergens Ara h 1, Ara h 2 and Ara h 3 are strong candidates for causing cross-sensitivity.     

Nutritional properties of medium-chain triglycerides

The biological effects of MCT (medium-chain triglycerides) differed from those of conventional fats, and certain of these suggested examination of the fatty acid composition and triglyceride structure of the adipose tissues and other organs of rats which were fed medium- or long-chain triglyceride mixtures with two levels of linoleic acid. Fatty acid compositions and TG patterns varied with the tissue, with the dietary fat, and with the level of linoleate in the diet. Increasing the latter resulted in the deposition of more linoleate at the expense of oleate and in the deposition of more of the dietary fatty acids. The percentage of completely saturated triglyc-erides (S₃), in adipose tissue with the higher linoleate supplement in the rats fed MCT, decreased in those fed LCT and was unchanged in the controls fed a fat-free diet. The increased deposition of the dietary fatty acids was more pronounced in the S₃ band. Supported by Grants U-1347 and U-1510 from the Health Research Council of the City of New York.