Is axial dispersion within rotating cylinders governed by the Froude number?

Axial dispersion rates of particles within horizontal rotating cylinders have been calculated for a decade of cylinder diameters. Throughout the range studied the rate of axial dispersion was found to be independent of the cylinder diameter. This phenomenon has been investigated further by spatially resolving the local contribution to the axial dispersion coefficient.

On the occurrence of polygon-shaped patterns in vibrated cylindrical granular beds.

We report experimental observations of polygon-shaped patterns formed in a vertically vibrated bed of circular cross-section. A phase map is determined, showing that the polygon pattern is established for Γ = A(2πf)(2)/g is > or approximately equal to 10. The sensitivity of the polygon structure to bed parameters was tested by studying beds of different particle sizes and fill levels.

Axial transport within bidisperse granular media in horizontal rotating cylinders.

The discrete element method has been used to examine axial dispersion within rotating cylinders containing two sizes of particle. Two bed configurations are considered: initially segregated, which consists of a pulse (narrow axial band) of small particles within a bed of large particles, and initially mixed, in which the cylinder is loaded with a homogeneous mixture of the two particle sizes. The dispersion of the small particles within initially segregated beds is found to depend strongly on the initial length of the pulse of small particles.

Increased fall risk is associated with elevated co-contraction about the ankle during static balance challenges in older adults.

Falls are a leading contributor to disability in older adults. Increased muscle co-contraction in the lower extremities during static and dynamic balance challenges has been associated with aging, and also with a history of falling. Co-contraction during static balance challenges has not been previously linked with performance on clinical tests designed to ascertain fall risk.

Circadian distribution of iron and ferritin in serum of healthy and type 2 diabetic males.

Aim: We examined the circulating levels of iron and ferritin in serum of seven healthy and three insulin non-dependent diabetic (Type 2) males in order to compare their circadian characteristics.

Methods: Blood samples were collected every 3h over a 24h period and were analyzed for serum iron and ferritin.

Results: The mean Fe level was significantly higher in healthy than in diabetic subjects: 80.

Altered circadian relationship between serum nitric oxide, carbon dioxide, and uric acid in multiple sclerosis.

The free radical nitric oxide (NO*) is involved in a variety of diverse biological processes from acting as a vasodilator in the cardiovascular system to being the rate-limiting component in the production of peroxynitrite (ONOO-), a contributor to neurodegenerative disorders such as multiple sclerosis (MS). Uric acid (UA), the end product of purine metabolism in humans and a selective inhibitor of toxic reactions attributed to radicals formed by the interaction of ONOO- and CO2, is generally low in MS patients. We investigated the relationship between serum ONOO-, CO2, and UA in MS patients and normal controls by comparing the circadian characteristics of the NO* metabolites nitrite/ nitrate (NO), CO2, and UA.

Circadian variation in oxidative stress markers in healthy and type II diabetic men.

Seven clinically healthy, nondiabetic (ND) and four Type II diabetic (D) men were assessed for circadian rhythms in oxidative "stress markers." Blood samples were collected at 3h intervals for approximately 27 h beginning at 19:00h. Urine samples were collected every 3 h beginning with the 16:00h-19:00h sample.

Day-night variations in blood levels of nitric oxide, T-TFPI, and E-selectin.

Circadian (8/24 hours) variations in serum nitric oxide (NO), total tissue factor pathway inhibitor (T-TFPI). and E-selectin levels were studied in healthy adults and in subjects with type II diabetes. We postulated a possibility a functional relationship between them because vascular endothelium is the primary site of their synthesis and functions.

Circadian variation of serum leptin in healthy and diabetic men.

Leptin, from the Greek leptos, meaning thin (in reference to its ability to reduce body fat stores), is a hormone secreted primarily by adipocytes. At one time, leptin was portrayed as a potential means of combating obesity. Recently, leptin has been identified as a potent inhibitor of bone formation, acting through the central nervous system.

Circadian rhythm of serum total homocysteine in men.

Serum homocysteine levels were examined in a 24-hour study of 7 healthy and 5 diabetic men, revealing a statistically significant circadian rhythm (p = 0.030), normal concentrations of 11.83 +/- 1.

Circadian interrelationships among levels of plasma fibrinogen, blood platelets, and serum interleukin-6.

Circadian (24 h) rhythms of fibrinogen, interleukin-6 (IL-6), and platelet levels were studied in 11 males ages 46 to 72 years. Since there is a known circadian rhythm for fibrinogen and IL-6, we postulated that the peak level (acrophase) of fibrinogen would follow the acrophase of IL-6, based on the fact that IL-6 is the stimulus for fibrinogen production in the liver. Platelet levels were measured to show whether there was any correlation with the IL-6 acrophase because it has been reported that IL-6 affects megakaryocytes and platelets in dogs.

Relation between circadian patterns in levels of circulating lipoprotein(a), fibrinogen, platelets, and related lipid variables in men.

Background: A correlation has been reported between lipoprotein(a) [Lp(a)] concentration and risk for coronary artery disease. High concentrations of Lp(a) might be markers for vascular or tissue injury or might be associated with other genetic or environmental factors that can cause acute myocardial infarction.

Methods: We measured the circadian characteristics of circulating Lp(a), fibrinogen, platelets, cholesterol, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol for a group of adult male volunteers who had no clinical symptoms.

Circadian relationships between circulating atrial natriuretic peptides and serum calcium and phosphate in healthy humans.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids (aa) 1 to 30, 31 to 67, and 99 to 126, respectively, of the 126-aa ANF prohormone circulate in humans. Among the biologic properties of these peptides is the ability of ANF to decrease intracellular calcium concentrations. To determine if atrial natriuretic peptides are directly related to serum calcium and/or phosphate in healthy normocalcemic humans, we examined 21 24-hour profiles of VSDL, LANP, ANF, and serum calcium and phosphate in 14 healthy humans.

Circadian relationships between circulating atrial natriuretic peptides and serum sodium and chloride in healthy humans.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids 1-30, 31-67, and 99-126 of the 126 amino acid ANF prohormone, respectively, circulate in humans and have potent natriuretic properties. To determine whether these peptides have a direct relationship to serum Na and/or Cl, we examined 21 24-hour profiles of these peptides and Na and Cl in 14 healthy humans. LANP, VSDL, ANF, and Cl had significant (p < 0.

Blood pressure and atrial natriuretic peptides correlate throughout the day.

Vessel dilator consisting of amino acids (a.a.) 31-67 and atrial natriuretic factor (ANF) composed of a.

Temporal (circadian) and functional relationship between atrial natriuretic peptides and blood pressure.

Long-acting natriuretic peptide, vessel dilator, and atrial natriuretic factor consisting of amino acids (a.a.) 1 to 30, 31 to 67, and 99 to 126 of the 126-a.

A quest for the relief of atherosclerosis: potential role of intrapulmonary heparin--a hypothesis.

Recent progress in the treatment of coronary artery disease is reviewed from the standpoint of changes in lifestyle, surgical techniques to revascularize the myocardium and a variety of medical interventions. Among the medical modalities, heparin appears to have a greater potential than any other agent tested to neutralize the atherogenic process at most of its stages. This potential is supported by success in clinical trials of heparin administered by intravenous, subcutaneous, pulmonary, sublingual and topical routes.

A major gene for primary hypoalphalipoproteinemia.

Sixteen kindreds were ascertained through probands clinically determined to have primary hypoalphalipoproteinemia, characterized by bottom decile high-density lipoprotein cholesterol (HDL-c), but otherwise normolipidemic. Age- and sex-adjusted, standardized HDL-c levels on 64 individuals in 14 nuclear families in which the proband was a parent were analyzed using the unified mixed model of segregation analysis as implemented in the computer program POINTER. The analysis proceeded by using the likelihood of offspring conditional on the parental phenotypes (conditional likelihood), which appears to overcome the limitation of possible heterogeneity in the selection criteria and provides an appropriate correction for the ascertainment.

Coronary risk factors and exercise test performance in asymptomatic hypercholesterolemic men: application of proportional hazards analysis.

The association of established coronary risk factors with submaximal graded treadmill exercise test performance was examined in 6,850 asymptomatic, white 34--59-year-old hypercholesterolemic men screened between 1973 and 1976 at 12 North American Lipid Research Clinics for participation in their Coronary Primary Prevention Trial. The prevalence of ischemic electrocardiographic responses (greater than or equal to 1 mm S-T segment depression) was 8.6%.

Primary and familial hypoalphalipoproteinemia.

Our specific aim was to assess within-family clustering of high-density lipoprotein cholesterol (HDLC) levels in kindreds identified through probands with primary hypoalphalipoproteinemia, and to determine whether, and to what degree, familial aggregation of HDLC less than or equal to the tenth percentile represents a heritable trait, familial hypoalphalipoproteinemia. Our probands were selected arbitrarily by virtue of HDLC less than or equal to the age-sex-race-specific tenth percentile as the sole dyslipoproteinemia, with an additional requirement that they be normotriglyceridemic (triglyceride levels less than the 90th percentile). The probands were also required to have primary hypoalphalipoproteinemia, not secondary to diseases and/or drugs.

A genetic study of hypoalphalipoproteinemia.

Complex segregation analysis under the unified mixed model of inheritance (major gene and multifactorial) is performed on families ascertained through 23 probands with hypoalphalipoproteinemia (depressed HDL-cholesterol, denoted HDL-c). Evidence for segregation of a recessive major gene for depressed HDL-c with frequency q = 0.116, in addition to multifactorial transmission (H = 0.

Studies of familial type III hyperlipoproteinemia using as a genetic marker the apoE phenotype E2/2.

Clinical symptoms, lipoprotein patterns, and apoE phenotypes were determined in 17 individuals with type III hyperlipoproteinemia (type III HLP) and in their relatives and spouses. The apoE phenotype E2/2 occurred in 15 type III HLP probands (88%) and the apoE phenotype E4/2 was found in 2 probands. In each of the families studied, the apoE phenotype inheritance was compatible with a model we previously proposed in which apoE is determined at a single genetic locus with three common alleles.