Cryogenic probe for low-noise, high-frequency electronic measurements

The design and performance of a low-noise, modular cryogenic probe, which is applicable to a wide range of measurements over a broad range of working frequencies, temperatures, and magnetic fields, is presented. The design of the probe facilitates the exchange of sample holders and sample-stage amplifiers, which, combined with its characteristic low transmission and reflection loss, make this design suitable for high precision or low sensitivity measurements. The specific example of measuring the shot noise of magnetic tunnel junctions is discussed. We highlight various design characteristics chosen specifically to expand the applicability of the probe to measurement techniques such as nuclear magnetic resonance.

Antiviral phenylpropanoid glycosides from the medicinal plant Markhamia lutea

Three new phenylpropanoid glycosides, named luteoside A (3), luteoside B (4), and luteoside C (5), were isolated together with the known compounds verbascoside (1) and isoverbascoside (2) from the roots of the medicinal plant Markhamia lutea. The structures of the new compounds were determined to be 1-O-(3, 4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-4-O- caffeo yl-6-acetyl-beta-d-glucopyranoside, 1-O-(3,4-dihydroxyphenyl)ethyl beta-d-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- caffeo yl-beta-d-glucopyranoside, and 1-O-(3,4-dihydroxyphenyl)ethyl beta-D-apiofuranosyl(1-->2)-alpha-l-rhamnopyranosyl(1-->3)-6-O- ferulo yl-beta-d-glucopyranoside, respectively, on the basis of chemical and spectroscopic data. All five phenylpropanoid glycosides exhibited potent in vitro activity against respiratory syncytial virus.

Predictors of nutritional supplement use by the elderly

We conducted a population survey to describe patterns and determine predictors of the use of nutritional supplements and single-ingredient vitamins and minerals among elderly living in five adjacent urban and rural counties in the Piedmont area of North Carolina. The stratified random sample consisted of 3939 black and white participants age 65 or older from the Duke Established Populations for Epidemiologic Studies of the Elderly. The use of nutritional supplements within the previous 2 weeks was determined during an in-home interview. Multivariate analyses, using weighted data adjusted for sampling design, were conducted to assess the association between nutritional supplement use and predisposing, need, and enabling factors. Nutritional supplement use was reported by 26.2% of participants and was more likely for those who were white women, were high school educated, were underweight, took prescription drugs, had five or more health visits in the previous year, and had supplemental health insurance. It was less likely for those with poor self-rated health. The majority (71.5%) of nutritional supplement users took at least one single-ingredient supplement. Use of such products was more likely in those who were white, born and raised in an urban area, and high school educated, and was less likely in those with impaired functional status. Nutritional supplement use is prevalent in community-dwelling elderly and is more commonly associated with demographic factors and access to health care than with need factors.

Calcium supplementation lowers serum parathyroid hormone levels in elderly subjects

To determine the effect of calcium supplementation on parathyroid hormone levels (PTH) in a group of elderly subjects at risk for developing Type II (senile) osteoporosis, 40 healthy volunteers participated in a randomized double-blind crossover study. Calcium carbonate or placebo was administered for 4 weeks, followed by a 4-week administration of the alternative intervention. Fasting blood samples and 24-hour urine collections were obtained at baseline, and at the end of each intervention period. Calcium supplementation (1000 mg/day) decreased serum PTH levels from a mean of 50.1 +/- 3.0 pg/ml to 41.9 +/- 2.4 pg/ml (p less than .001). Additionally, urine calcium excretion significantly increased during calcium administration (from 3.64 mmol/mmol creatinine at baseline to 4.28 mmol/mmol creatinine), but creatinine clearances and serum calcium levels remained unchanged. Type II osteoporosis has been associated with age-related increases in PTH levels. We have demonstrated the ability of increased calcium intake to decrease these levels, which may have implications for the management of a subset of patients with involutional osteoporosis.

Cytologic diagnosis of gastric cancer

Follow-up of cytologic examinations of specimens obtained from 187 patients by gastric lavage with saline solution, without the use of enzymes or abrasive devices, showed a false positive rate of 0.6 per cent and a false negative rate of 17 per cent. To achieve satisfactory results with such examinations, great attention to detail in obtaining, preparing and examining the specimens is essential. Cytologic examination should be done in any case in which gastric cancer is suspected clinically or roentgenographic or gastroscopic findings arouse suspicion.