Note: electrochemical etching of silver tips in concentrated sulfuric acid.

Sharp metal tips have many uses, including in scanning probe microscopy. Silver is a particularly interesting metal for plasmonic enhancement, e.g., in tip-enhanced Raman spectroscopy, however few methods for the production of silver tips have been explored. A simple and reliable one step dc electrochemical method for the production of sharp silver tips in concentrated H2SO4 is presented. The optimal conditions are 10 V cell voltage and 99% sulfuric acid for tip radii below 100 nm. A LabView program was written to control the cut-off of the circuit to within a millisecond to avoid blunting the tips after drop-off.

Inducibility of metallothionein mRNA expression and cadmium tolerance in larvae of a marine teleost, the turbot (Scophthalmus maximus).

An acute (48-hr) lethal toxicity study of turbot at various stages from hatch to juveniles showed that prior to first exogenous feeding, larvae of turbot were an order of magnitude more sensitive to cadmium toxicity than later developmental stages (LC50 of 0.18-0.23 ppm Cd versus 2-5 ppm Cd). To investigate the possible role of metallothionein (MT) in Cd tolerance, the concentrations of MT mRNA were determined in control and Cd-exposed animals using a plaice MT cDNA probe. MT mRNA was expressed throughout embryonic and early larval development at levels approximately twice those in juvenile turbot liver apart from the period around hatching, when there was a decreased level of expression. During endogenous feeding, despite larval drinking, MT mRNA levels did not appear to be inducible by exposure to Cd in the water within 3 days of hatching but were induced three- to fivefold after 48 hr exposure to waterborne Cd at all later stages of development. The results suggest that Cd tolerance is associated with metal induction of MT gene transcription and that the enhanced sensitivity of very early stage larvae is attributable to a deficiency in MT gene transcription.

Molecular cloning of troponin I expressed in fast white muscle of a teleost fish, the Atlantic herring (Clupea harengus L.).

By cDNA cloning and 5'-RACE analysis we characterised a Clupea harengus troponin I mRNA expressed in larvae and in adult white (fast) muscle, but not in red (slow) or cardiac muscle. The mRNA encodes a TnI protein of the short chain length (176 residues) N-terminally truncated type previously observed only in tetrapod skeletal muscles. Despite its expression specificity the herring TnI does not particularly resemble the tetrapod fast skeletal muscle isoform in sequence but appears to be outside of the tetrapod TnIfast/Tnslow/TnIcardiac isoform family. Surprisingly, the actin/TnC-binding sequence resembles that of arthropod, rather than tetrapod vertebrate, troponin I's and has, besides, unique features not seen in any other troponin I's, vertebrate or invertebrate.

Total cholesterol and lipoproteins in school children: prediction of coronary heart disease in adult relatives.

The distribution of risk factors and the prevalence of coronary heart disease (CHD) were studied in 850 first- and second-degree relatives of 98 healthy index cases selected from 3666 school children surveyed for lipid levels in Rochester, Minnesota. Three groups of families were based on an index child's total plasma cholesterol level: 18 families with a child in less than the fifth percentile (low-cholesterol group), 47 with a child in the fifth to ninety-fifth percentiles (middle-cholesterol group) and 33 with a child in greater than the ninety-fifth percentile (high-cholesterol group). The children's cholesterol levels clustered with those of their relatives; mortality due to CHD before age 65 was increased by 2.5 times in grandfathers of index cases in the high-cholesterol group compared with those of the middle-cholesterol group (p less than 0.016). The prevalence of CHD in all the grandfathers was associated with an index child's total cholesterol, more strongly associated with an index child's low-density lipoprotein cholesterol level and most strongly associated with an index child's high-density lipoprotein cholesterol level as a fraction of total cholesterol. This study establishes that childhood lipid and lipoprotein levels from a single cross-sectional survey identify families at elevated risk for CHD.

Cholesterol and triglycerides in serum lipoproteins of young persons in Rochester, Minnesota.

Cholesterol and triglyceride levels in whole sera and in the major lipoprotein fractions are presented for 2,421 children and youths in Rochester, Minnesota, ranging in age from 6 to 18 years. This cross-sectional study revealed subtle changes associated with puberty and the occurrence of certain additional sex-specific changes related to age. Hyperlipoproteinemia was detected in 101 youngsters; those cases exemplified types IIa (61 cases), IIb (5 cases), III (5 cases), and IV (30 cases). One case of type V hyperlipoproteinemia was observed in a second and comparable population sample of 1,245 young persons.

Nutrient intake and serum cholesterol level in normal children 6 to 16 years of age.

A study of 103 healthy, white schoolchildren who were between 6 and 16 years of age revealed no positive correlation between the level of serum cholesterol and the mean daily amount of total calories, cholesterol, fat, saturated fat, or sugar in the diet.

The many faces of food--as seen through the eyes of the artist.

Artists through the ages have displayed an interest in food, not only for its nourishing value but also for its aesthetic nature. Consequently, the art world has endowed the field of nutrition with a colorful record of the artistic merits and heritage of food. In this article, the author explores some of the food lore depicted in various famous paintings. Such insights should be rewarding to anyone who enjoys pictorial art as an avocation--and especially to those whose vocation involves food. As knowledge of food and eating customs increases, so also does the appreciation for the theme of a painting, the intent of the artist, and the culture that nourished both his palate and palette.

Comparison of serum cholesterol in children fed high, moderate, or low cholesterol milk diets during neonatal period.

The long-term effects of milk diets in infancy on the blood serum cholesterol concentrations were studied in 97 school children 7-12 yr of age. Detailed histories were available for these children with respect to their diets during infancy. The major criterion for inclusion in the study was milk (human milk, cow's milk, or commercial formula) as the exclusive source of diet cholesterol during the first 3 mo of life. Fasting blood cholesterol and triglycerides were measured in these 97 school children, and the current diets of 29 of the 97 were evaluated for daily cholesterol intake. A 7-day diet diary was recorded, the food intake was measured and analyzed for nutrients, and validity of the diets was verified by determination of urinary nitrogen excretion. Results of the study showed that the school children fed a low cholesterol formula during infancy had a mean serum cholesterol value 7-12 yr later that was lower than the mean values of the groups fed greater amounts of cholesterol in infancy. Analysis of current diets of 29 of the 97 school children showed that their current dietary intake of cholesterol was low. Dietary intake of cholesterol did not have a noticeable effect on the serum cholesterol levels of the 29 children.