Energy structure of a finite Haldane chain in Y2BaNi0.96Mg0.04O5 studied by high field electron spin resonance.

This Letter presents the fine structure of energy levels for the edge states of a Haldane chain. In order to investigate the edge states, we have performed high field and multifrequency electron spin resonance (ESR) measurements of finite length S=1 antiferromagnetic chains in Y2BaNi0.96Mg0.04O5. Owing to the high spectral resolution by high fields and high frequencies, observed ESR signals can be separated into the contributions of the finite chains with various chain lengths. Our results clearly show that the edge spins actually interact with each other through the quantum spin chain and the interaction depends on the chain length N. This N dependence has been obtained experimentally for the first time, and shows that the correlation length xi in the real system is somewhat larger than that calculated by a simple Heisenberg model.

Midazolam for continuous sedation in Japanese critical care patients: phase II study.

This prospective study was undertaken to evaluate the efficacy and safety of midazolam as a sedative agent in 14 critically ill patients without coma admitted to the intensive care unit at Nihon University Itabashi Hospital, Japan. Adequate sedation (sedation score [SS] 4-6) was induced with 0.058- 0.372 mg/ kg midazolam and maintained with a dose range of 0.03-0.4 mg/kg per h. Most burn or trauma patients required higher midazolam doses than patients with cardiovascular disease. The most frequent adverse events observed were hypotension, heart-rate fluctuation and electrocardiogram abnormalities. Pharmacokinetic analysis of the population suggested that lower drug clearance rates correlated with presence of complications. Plasma concentrations (EC50) of SS 5, estimated by logistic regression analysis, varied among patients (mean 194 ng/ml). Midazolam infusion achieved successful sedation in this critical care setting, but the optimum dose differed by patient and was influenced by the presence of complications.

Can plasma glucose and nonesterified fatty acid be regulators of glucose utilization in skeletal muscle?

The effect of plasma glucose and nonesterified fatty acid (NEFA) on basal and insulin-stimulated glucose utilization in skeletal muscle was assessed by perfused hindlimb preparations. Two-month-old male Wistar rats were divided into four groups: starved, glucose-loaded, hypoglycemic and control. Diabetic rats were made by means of streptozotocin, and divided into three groups: non-treated, insulin-treated normoglycemic and insulin-treated hyperglycemic. The effect of NEFA on glucose clearance was also investigated by adding palmitate to the perfusate. Basal glucose utilization decreased with a rise in plasma glucose concentrations, and increased with a fall in them in each group. The available data strongly support the view that plasma glucose levels play an important role in the control of basal glucose utilization by the hindlimb muscle. In contrast, continuous hyperglycemia in the diabetic state decreased insulin-stimulated glucose utilization by the skeletal muscle, whereas an acute rise in plasma glucose concentrations in the glucose-load state did not. Palmitate stimulated basal glucose utilization, while it decreased insulin-stimulated glucose uptake. It was also clarified that it increased the affinity for glucose in the skeletal muscle in the basal state. This finding seems to indicate that NEFA has some influence on an increase in basal glucose utilization in starvation.