Chain matching between hydrocarbon and fatty acid as interfacial phenomena

According to the investigations of Cameron and his coworkers^1–5 into the chain-matching phenomena between normal paraffin as a solvent and straight-chain fatty acid as an additive, the optimum condition in boundary lubrication is attained when the chain lengths of the additive and solvent are equal. A series of experiments has been conducted over the past ten years on the role of the chain-matching effect, not only on boundary lubrication but also widely on relevant interfacial phenomena. The results of the investigations are discussed.     

Synthesis of the Bi-2222 Compounds of Bi–Sr–Ln(Zr)–Cu–O (Ln = Sm,Eu, Gd,and Dy)

Bi-based superconducting compounds with the 2222 structure has been already synthesized in the Bi₂Sr₂- (Ln_1−x Ce _x )₂Cu₂O_10+y (Ln = Sm, Eu, and Gd) systems. One of the characteristics of these compounds is the existence of the fluorite-like (Ln_1−x Ce _x )₂O₂ block between two CuO₅ pyramids in the crystal structure. The tetravalent ions of Ce⁴⁺ are reported to be necessary to stabilize the 2222 structure. Recently, we have discovered that the Bi-2222 phase could be composed in the Bi₂Sr₂(Ln_2−x Zr _x )Cu₂O _z (Ln = Sm, Eu, Gd, and Dy) systems, where Zr⁴⁺ is used as a new tetravalent ion stabilizing the 2222 structure in stead of Ce⁴⁺. In the new system, nearly single 2222 phase samples have been obtained at the nominal composition of x=0.5 (Ln = Sm, Eu, and Gd) and in the range of 0.1≤x≤0.3 (Ln = Dy). Among them, the sample with Ln = Gd has the smallest resistivity at 273 K. But it is a semiconductor, and the conduction process at low temperatures is assumed to be followed by a two-dimensional VRH. The experimental results for the Gd samples with a partial substitution of Pb for Bi in the Bi₂Sr₂(Gd_2−x Zr _x )Cu₂O _z system are also reported.     

Visualization of the information flow through human oculomotor cortical regions by transcranial magnetic stimulation

We investigated the topography of human cortical activation during an antisaccade task by focal transcranial magnetic stimulation (TMS). We used a figure-eight shaped coil, with the stimulus intensity set just above the threshold for activation of the hand motor areas but weak enough not to elicit blinks. TMS was delivered at various time intervals (80, 100, and 120 ms) after target presentation over various sites on the scalp while the subjects performed the antisaccade task. It was possible to elicit a mild but significant delay in saccade onset over 1) the frontal regions (a region 2-4 cm anterior and 2-4 cm lateral to hand motor area) and 2) posterior parietal regions (6-8 cm posterior and 0-4 cm lateral to hand motor area) regardless of which hemisphere was stimulated. The frontal regions were assumed to correspond to a cortical region including the frontal eye fields (FEFs), whereas the parietal regions were assumed to represent a wide region that includes the posterior parietal cortices (PPCs). The regions inducing the delay shifted from the posterior parietal regions at an earlier interval (80 ms) to the frontal regions at a later interval (100 ms), which suggested an information flow from posterior to anterior cortical regions during the presaccadic period. At 120 ms, the effect of TMS over the frontal regions still persisted but was greatly diminished. Erroneous prosaccades to the presented target were elicited over a wide cortical region including the frontal and posterior parietal regions, which again showed a forward shift with time. However, the distribution of effective regions exhibited a clear contralateral predominance in terms of saccade direction. Our technique provides a useful method not only for detecting the topography of cortical regions active during saccadic eye movement, but also for constructing a physiological map to visualize the temporal evolution of functional activities in the relevant cortical regions.     

The individual difference of response to the negative side of self-enhancing presentation

In this study, scales were developed to measure responses to negative aspects of others' and own self-enhancing presentation, and relationships among the scales and self-consciousness were examined. With factor analysis, the scale for responses to others' self-enhancing presentation was divided into three subscales: emotional, critical, and empathic. The scale for those of own self-enhancing presentation was similarly divided into three: disliking, analytical, and accepting. The scales and self-consciousness scale (translated by Sakamoto, 1989) were administered to 373 university and professional school students (204 male and 169 female). The main findings were as follows: 1) Self-disliking and analytical subjects had high public self-consciousness and social anxiety, and tended to show high emotionality toward other's self-enhancing presentation. 2) Self-accepting subjects had high public self-consciousness, and responded empathically, but not emotionally, to other's self-enhancing presentation.     

Lysophosphatidylcholine potentiates the mitogenic activity of modified LDL for human monocyte-derived macrophages

The growth of murine peritoneal macrophages is induced by oxidized LDL (Ox-LDL), and lysophosphatidylcholine (lysoPC) plays an important role in its mitogenic activity. In the present++ study, Ox-LDL-induced macrophage growth was examined with human monocyte-derived macrophages. The cell growth of human macrophages was significantly induced by Ox-LDL but not by acetylated LDL (acetyl-LDL). The treatment of acetyl-LDL with phospholipase A2, however, led to a marked increase in its mitogenic activity, with a concomitant conversion of 75% of its phospholipids to lysoPC. The growth-stimulating activity became positive only when both acetyl-LDL and lysoPC were coincubated, although neither of them exhibited cell growth-promoting activity. These results suggest that Ox-LDL could stimulate the growth of human monocyte-derived macrophages, and lysoPC may play an essential role in the mitogenic activity of Ox-LDL.     

delta-Aminolevulinic acid in plasma or whole blood as a sensitive indicator of lead effects, and its relation to the other heme-related parameters

To evaluate the subclinical effect of lead exposure, we determined delta-aminolevulinic acid (ALA) levels in plasma (ALA-P), blood (ALA-B), and urine (ALA-U) and the activity of delta-aminolevulinic acid dehydratase (ALAD) in lead workers. Almost all of the ALA molecules in blood were present in plasma and not in blood cells, irrespective of the blood lead concentration (Pb-B). ALA-P or ALA-B levels increased slowly at Pb-B levels below 40 micrograms/dl (slow phase) and rapidly at levels above 40 micrograms/dl (rapid phase). In both phases, ALA-P and ALA-B were well correlated with Pb-B and ALAD activity. The threshold value (no-effect level) of Pb-B for elevation of the ALA-P or ALA-B level was coincident with that for ALAD inhibition; the value was around 5 micrograms/dl. In the rapid phase, ALA-P increased continuously up to 100 micrograms/dl of Pb-B, while ALAD activity reached a plateau. Receiver operative characteristic (ROC) plot analyses indicated that ALA-P and ALAD activity [ALAD(u)] had a similar diagnostic value at Pb-B levels between 10 and 40 micrograms/dl, although ALAD(%), the remaining ALAD activity as a percentage of the whole activity restored by zinc and dithiothreitol, had the most powerful diagnostic efficiency at these Pb-B levels. By contrast, ALA-U and zinc protoporphyrin were less effective for the diagnosis of lead exposure than ALAD and ALA-P. These findings indicate that ALA-P is the best discriminators of lead exposure form baseline to high levels of exposure.     

Expression of endothelial and inducible nitric oxide synthase in human glomerulonephritis

The presence of nitric oxide (NO) in the kidney has been implicated in the pathogenesis of human glomerulonephritis. However, the exact type of glomerular cells that express NO synthase (NOS) and the NOS isoform involved in the local production of NO has not been identified in the human diseased kidney. We examined the expression of three isoforms of NOS, inducible NOS (iNOS), endothelial NOS (eNOS) and brain NOS (bNOS) in the renal tissue of patients with IgA nephropathy (IgAN, N = 10), lupus nephritis (LN, N = 5), membranous nephropathy (MN, N = 5) and minimal change nephrotic syndrome (MCNS, N = 5). Sections were immunostained and the correlation between the expression of each NOS and the degree of glomerular injury in that section was also examined. Normal portions of surgically resected kidneys served as controls. eNOS was present in glomerular endothelial cells and endothelium of cortical vessels in the control and diseased kidneys. iNOS was localized in mesangial cells, glomerular epithelial cells and infiltrating cells in the diseased glomeruli, whereas immunostaining for iNOS was hardly detected in control kidneys. In addition, the expression pattern of eNOS in each glomerulus was the reverse of that of iNOS. In IgAN and LN, the extent of staining for eNOS correlated negatively with the degree of glomerular injury, while the extent of staining for iNOS correlated positively with the degree of glomerular injury in the same tissues. bNOS was not detected in normal or nephritic glomeruli. Our results indicate the presence of a NO pathway in human diseased kidney, and suggest that NO derived from eNOS and iNOS may be involved in the progression of renal diseases and that NO derived from each NOS may play an important role in different way in human inflamed glomeruli.     

A case report of chronic dissecting aortic aneurysm (Stanford type A) with circumferential detachment of the intima

A 57-year-old man underwent Bentall's procedure (Piehler's modification) and partial aortic arch replacement for Stanford type A chronic aortic dissection. Circumferential detachment of intima with intimal intussusception into the aortic arch was found at the time of operation. Preoperative findings did not show the intimal tear involving entire circumference of the ascending aorta. He was asymptomatic but coughing before consulting our hospital. He was discharged from the hospital 26 days after operation.     

The MHD effect and its relaxation process on electric current in the electrolysis of ferricyanide reduction and ferrocyanide oxidation

The electrolytic reduction of ferricyanide and the electrolytic oxidation of ferrocyanide have been carried out with exposing the magnetic field of 1000 or 1800 gauss. The current clearly increased after the magnetic exposure. The maximum current was obtained when the magnetic flux directed in parallel with the surface of electrode. These are speculated in terms of magnetohydrodynamic mechanism. The current decrease caused by relaxation process was observed after the removal of magnetic flux. The relaxation time obtained was temperature-dependent. Therefore the values of apparent transition energy, E_trans, were determined from the Arrhenius' plots of relaxation time against temperature. The magnitude of E_trans was dependent on the concentration of ferricyanide or ferrocyanide, and the viscosity and the conductivity of electrolyte solution. The activation energy of viscosity of electrolyte solution was compared with E_trans. As a conclusion, it was suggested that E_trans may be influenced by the velocity of magnetohydrodynamic flow, which was controlled by the diffusion current in electrolysis and the viscosity of electrolyte solution.