Cyclopropene fatty acids of selected seed oils from bombacaceae,malvaceae, and sterculiaceae

Fatty acid compositions of seed oils from three species of Bombacaceae, eleven from Malvaceae, and six from Sterculiaceae were determined. Each of the seed oils contains varying amounts of both malvalic and sterculic acids accompanied by one or both of the corresponding cyclopropane fatty acids. In addition, the seed oil ofPachira aquatic Aubl. (Bombacaeae) contains 12.8% α-hydroxysterculic acid.     

γ-Linolenic acid inAcer seed oils

The octadecatrienoic acids inAcer negundo L. (maple family) seed oil include both 9,12,15- (1%) and 6.9,12-(7%) isomers. The chief monoenoic acids identified were 9-octadecenoic (21%), 11-eicosenoic (7%), 13-docosenoic (15%), and 15-tetracosenoic (7%). Also present is a considerable amount of 9,12-octadecadienoic acid. Investigation of ten other Aceraceae revealed their seed oils to have a similar fatty acid composition.     

Dihydrosterculic acid,a major fatty acid component ofEuphoria longana seed oil

The seed oil ofEuphoria longana, Sapindaceae, contains 17.4% of 9,10-methyleneoctadecanoic (dihydrosterculic) acid. This identification is based on information from thin layer chromatography, infrared analysis, gas liquid chromatography, nuclear magnetic resonance and mass spectroscopy. Since GLC of the oil showed components that emerged between the usual triglycerides, the cyclopropanoid acid is apparently a triglyceride constituent. The presence of smaller amounts, less than 1%, of cyclopropanoid fatty acids of different chain lengths is indicated by GLC and TLC analyses of the methyl esters. The other major fatty acids in this oil are: 16∶0 (19%), 18∶0 (7%), 18∶1 (36%), 18∶2 (6%), 18∶3 (5%) and 20∶0 (4%).Euphoria oil contains considerably larger amounts of cyclopropanoid fatty acids than previously reported in other seed oils. Presented at the AOCS-AACC Joint Meeting, Washington, D.C., April 1968. No. Utiliz. Res. Dev. Div.; ARS, USDA.     

ICRP PUBLICATION 118: ICRP Statement on Tissue Reactions and Early and Late Effects of Radiation in Normal Tissues and Organs - Threshold Doses for Tissue Reactions in a Radiation Protection Context

This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.     

Creep phenomena in lead-free solders

A critical review of data on microstructure and creep process activation energy values for a number of lead-free solder alloys like Sn-Ag; Sn-Bi; Sn-In was conducted. The review revealed a scatter in experimental data, which could not be explained by the dislocation creep mechanism only, even after the published data was corrected for Young’s modulus temperature dependence. An analysis of the data implies that possible origin of such a scatter is nucleation, accumulation and further growth of such internal defects as pores and microcracks during creep. It is shown that these processes may affect the measured steady-state creep rates, and may be one of the major reasons for the observed scatter in experimental data, and, therefore, must be taken into consideration in lead-free solder alloys’ creep studies.     

Meadowfoam monoenoic fatty acid amides as slip and antiblock agents in polyolefin film

Mixed monounsaturated amides (MMA) of fatty acids from meadowfoam (Limnanthes alba) were effective slip and antiblocking agents for polyethylene films. MMA may compete with extant amides as additives for manufacture of PE films if their selling price is competitive. The MMA (79% cis-5-eicosenoic acid amides, 17% cis-5-, and cis-13-docosenoic acid amides, and 1% cis-5, cis-13-docosadienoic acid amide) required > 500 ppm but < 1000 ppm dosage to achieve high slip (coefficient of friction < 0.2) within 10 minutes of film blowing. For comparison, erucamide required < 250 ppm, oleamide required < 500 ppm, and stearamide required > 1000 ppm to give high slip levels within 10 min. Maximum antiblocking effectiveness of MMA, which developed at 1000 ppm, was equivalent to stearamide at 1000 ppm. © 1993 John Wiley & Sons, Inc.^§     

A detailed triglyceride analysis ofLesquerella fendleri oil: Column chromatographic fractionation followed by supercritical fluid chromatography

The triglyceride structure of oil fromLesquerella fendleri, a potential new U.S. crop, rich in C₂₀ hydroxy fatty acids, was examined by silica gel column chromatographic fractionation followed by supercritical fluid chromatography. The analysis confirmed previous findings derived by our research group, but provided further detail. The analysis demonstrated the presence of trihydroxy triglyceride, which contained all of the oil’s C₁₈ hydroxy acyl groups (present at less than 0.5% in the oil). Lipolysis indicated that these groups were located solely at the 2-position. In addition, a strong correlation was detected between the presence of α-linolenic (18:3^9,12,15) and auricolic (20:2^11,17 OH¹⁴) acids in triglycerides.     

Fatty acid composition ofcuphea seed oils

Nineteen species of 10 taxonomic sections ofCuphea were analyzed for fatty acid composition of the seed oils. Two sections of the genus,Trispermum andPseudocircaea, previously unreported, are included. Lauric acid is the major component of the seed oil in seven of the species surveyed; capric andmyristic each predominate in five. Linolenic acid, previously thought to be only a trace component ofCuphea seed oils, is the major constituent of two species. Two others are rich in linoleic acid, another minor component of mostCupbea oils.     

cis-5-Monoenoic fatty acids in some chenopodiaceae seed oils

Methyl esters from seed oils of four Chenopodiaceae species are unusual in that they contain methylcis-5-hexadecenoate (4.6–12%) and methyl 5-octadecenoate (1.1–1.2%). There are indications of small amounts of 18∶2^5,9 and 18∶3^{5, 9, 12} along with unsaturated acids commonly found in seed oils-oleic (14–21%), linoleic (53–57%) and linolenic (3.5–7.8%). Fatty acid composition of the oils was determined by gas chromatography, and positions of the double bonds were established by application of gas chromatography-mass spectrometry to the methoxylated methyl esters. N. Market. Nutr. Res. Div., ARS, USDA.