Increase In Peak Height Research Articles

Indications for the presence of sulfate esters as considerable metabolites of Sunset Yellow FCF and Orange GGN in rat faeces

Male Wistar rats received by stomach intubation 500 mg/kg of the azo dyes Sunset Yellow FCF and Orange GGN. Previous work revealed that in the Sunset Yellow FCF as well as in the Orange GGN aqueous faeces extracts a considerable orange metabolite is present, eluting as a strong peak before the unchanged dye after ion-pair reverse-phase liquid chromatography (RP-IP-HPLC). Incubation of both aqueous faeces extracts with arylsulphatase followed by high-performance liquid chromatography (HPLC) analysis, resulted in a significant orange metabolite peak height decrease together with a noticeable unchanged dye peak height increase. By means of semi-preparative HPLC, combined with cation-exchange purification, the orange Sunset Yellow FCF faeces metabolite could be isolated. It was identified by means of FT- 1HMR spectroscopy as a Sunset Yellow FCF structurally related compound with the same 1HMR pattern, which is therefore modified on the free aromatic hydroxyl group.

Time parameters of contraction of inotropically responding cultured heart cells in relation to cellular cyclic AMP levels

Television video microscopy combined with photoelectric recording was used to determine the influence of a number of positive inotropic agents on the amplitude (peak height) and the course of the contraction of electrically paced myocytes in 4-day monolayer cultures derived from the heart ventricles of 1 to 2-day old rats. Cyclic AMP was determined in parallel cultures of the same cell population. Reductions in time to 90% of peak height, 90% of relaxation time, and duration of contraction caused by peak height-augmenting concentrations of isoproterenol, epinephrine, dibutyryl cyclic AMP, and 1-methyl-3-isobutylxanthine, but not of theophylline, correlated with rises in cellular cyclic AMP levels. Ouabain, a rise in extracellular CaCl 2, and, in some experiments, phenylephrine in the presence of propranolol increased peak height, but did not change time to 90% of peak height, 90% of relaxation time, duration of contraction, and cyclic AMP content. These responses are compared to those observed by other authors in intact cardiac muscle and are discussed in the light of evidence linking increased myocardial cyclic AMP levels with an abbreviation of systole.

The correlation of antiwear properties with the chemical reactivity of zinc dialkyldithiophosphates

The chemical reactivity of zinc dialkyldithiophosphates (ZnDTPs) with iron was investigated using differential thermal analysis (DTA). The antiwear property was examined with a cross-pin-type lubricant tester. The types of alkyl groups in the ZnDTPs were identified by DTA. With primary alkyl ZnDTPs, an exothermic peak was observed, corresponding to the formation of FeS. The wear scar diameter increased with increase in peak height. Corrosive wear may be a dominant factor. With secondary alkyl ZnDTPs, an endothermic valley and an exothermic peak were observed at temperatures near 200°C. No reaction product was detected beyond the valley and the peak. FeS was detected as a reaction product at the second exothermic peak, which was observed at a higher temperature than those of the valley and the peak. The wear scar diameter decreased with increase in the height of the second peak. Secondary alkyl ZnDPTs may behave as non-sacrificial extreme pressure additives.

A Numerical Study of Mass and Energy Transfer of Surface, Surface Boundary Layer and Planetary Boundary Layer

The horizontal inhomogeneity is a common occurrence in the lower layer of the atmosphere. For example, in land-lake interface problems, and in flows over finite areas of irrigated land, abrupt changes of surface conditions, i. e., roughness, temperature and humidity occur simultaneously, and the profiles are no longer in equilibrium. The principal purpose of this paper is to present these phenomena quantitatively from a theory.In this study, we used the same numerical method as Estoque and Bhumralkar (1970) describing a finite-difference procedure for numerical integrating the planetary boundary-layer equations. According to the similarity theory expressed as those equations, the thermal stability was assessed in terms of Richardson number (Ri). The evaluation of the Ri is open to question because it is based on the doubtful assumption that the stability condition of the planetary boundary layer is equal with height. If the surface of the earth is heterogeneous as mentioned above, the flow pattern, temperature and humidity field must change with its surface characters. In this case, one should have a more the appropriate parameter in describing the internal boundary layer.In order to take the varying stability conditions with height into consideration, Hayakawa et al. (1979) suggested to use a gradient Richardson number (Rig) for the stability parameter. The flow pattern with the Rig shows that the prevailing flow accelerates on encountering the windward edge of a localized heat source (LHS) and decelerates on leaving the leeward edge. As a consequence of the horizontal velocity variations there is a downwind above LHS and an upward motion in most part of the leeward area. The characteristics of this flow pattern with the Rig is completely contrary to Hayakawa's results (1978) based on Rib. It can be that the reason for these serious differences are due to the different diffusion coefficient caused by a different definition of Ri.The profiles of the diffusion coefficient (K) obtained by use of Rig show its peaks at reasonable levels, and the values of K and the peak height increase with the scale of LHS. These characteristics agree qualitatively well with the observation results of the planetary boundary layer.The perturbation of potential temperature based on the Rig can not develop in an altitude so high and horizontally so extensive as the case with Rib.By an analysis of the condition that the perturbation of potential temperature vanishes in the atmospheric boundary layer, we have reached to the conclusion that the inertial term is more important in the “cross-over” phenomenon than the bouyant force.We define ZH, which is decided from the potential temperature profiles (Fig. 6) and Ri profiles (Fig. 2), as a thickness of the atmospheric boundary layer, and have examined the growth of the internal boundary layer thickness with fetch (x). We have compared these values of thickness obtained from the simulation experiment with those obtained from analytic expressions by other researchers. As a result, the best linear fit was obtained from Kimura's expression (ZH∝R-1/6·x), and Sutton's expression (ZH∝K1/2·x1/2·U-1/2) followed.When air moves from a cool area to a hot one, the horizontal temperature gradient ∂T/∂x becomes positive above the hot area, then the gradient of vertical sensible heat flux ∂H/∂z becomes positive above that area. On the other hand, when air moves from a hot area to a cool one, ∂T/∂x and ∂H/∂z become negative above the cool area.

Transmembrane phospholipid motions induced by F glycoprotein in hemagglutinating virus of Japan

Transfer of phospholipid from the envelope of hemagglutinating virus of Japan (HVJ) to erythrocyte (RBC) membrane and the virus-induced transfer of phospholipid between RBC membranes were studied using spin-labeled phosphatidylcholine (PC). The transfer of PC from membranes labeled densely with PC to unlabeled membranes was followed by the peak height increase in the electron spin resonance spectrum. The two kinds of transfer reactions took place very rapidly as reported previously. To obtain further details, the transfer reactions were studied with HVJ, HVJ inactivated by trypsin, HVJ harvested early, HVJ grown in fibroblast cells, the fibroblast HVJ activated by trypsin, influenza virus, and glutaraldehyde-treated RBCs. The results demonstrated that the viral F glycoprotein played a crucial role in the transmembrane phospholipid movements as well as in the fusion and hemolysis of RBCs. The transfer from HVJ to RBC's occurred partially through an exchange mechanism not accompanying the envelope fusion. This was shown by a decrease in the exchange broadening of the electron spin resonance spectrum of released spin-labeled HVJ (HVJ) and also by an increase in the ratio of PC to viral proteins incorporated into RBC membranes. HVJ modified RBC membrane so as to be able to exchange its phospholipids with those of inactive membranes such as fibroblast HVJ, influenza virus, glutaraldehyde-treated RBC'S, and phosphatidylcholine vesicles. HVJ affected the fluidity of RBC membranes markedly, the environments around PC being much fluidized. The virus-induced fusion was discussed based on close apposition of the membranes by HANA proteins and on the destabilization and fluidization of RBC membranes by F glycoproteins.

A specific protein abnormality associated with cobalt-induced epilepsy in mice

Density profiles of protein patterns from cortical tissue exhibit an increase in only one peak when mice are rendered epileptic by application of cobalt to the cortex. The increase and diminution in peak height, attributed to a change in the concentration of a single protein (protein 3), coincides with the severity of seizure activity; with the degree of abnormality of the cortex region affected; and with the time of onset, duration, and disappearance of the epileptic condition. Thus, the concentration of protein 3 is highest in tissue from the site of cobalt application (up to 10× normal), is increased less in the focus (up to 5× normal), while in the mirror focus (contralateral, not exposed surgically), the increase in the concentration of protein 3 is still detectable, but not as pronounced. The concentrations in these cortex regions decrease to normal in reverse order to their elevation when the epileptic signs begin to diminish. Furthermore, the increase of protein 3 in all three areas is proportional to the severity of epilepsy. The concentration of protein 3 also becomes enhanced when the cortex is injured, but no progressive increase in the concentration occurs with time, nor does the concentration reach that observed in the site of cobalt application or the focal region. These mice do not exhibit spontaneous seizures, but injection of pentelynetetrazol confirms that animals with brain injury only are more susceptible to seizures. The results of this study suggest that both the area of cortex affected and the intensity of metabolic alterations may be precipitating factors in establishing an epileptic condition. This view is in agreement with clinical observations on epilepsy.

Changes of Action Potential Shape and Velocity for Changing Core Conductor Geometry

The theoretical changes in shape and velocity of an action potential were computed in regions of changing core conductor geometry. Step decrease and step increase of diameter, branch points, and gradual taper or flare of diameter were studied. Results showed increase of both velocity and peak height as the action potential approaches a point of step decrease. A step increase causes decrease of both velocity and peak height with approach; propagation may either fail, succeed with brief delay, or, with longer delay, succeed in both forward and reverse directions. With branching, both the shape and the dimensionless velocity, tautheta/lambda, remain unchanged when the d(3/2) values are matched. Without such matching, the changes of shape and dimensionless velocity of an action potential correspond to those found for step decrease or step increase of diameter. For regions of flare or taper, it was found (for a specific previously defined class) that velocity changed in proportion with the changing length constant. A simple formula was found to predict how this proportionality constant depends upon the amount of flare or taper.

Physical growth and development of urban and rural East African children, aged 7-16 years.

SummaryLongitudinal data on the growth and development of African boys and girls attending an urban primary school in Dar es Salaam during the years 1966–1971 together with cross-sectional height and weight data of children aged 7–15 years attending urban and rural schools in Tanzania are presented. No significant differences were found between the two groups and standards of height and weight, skinfold thickness and arm circumference are given. The data suggest that though East African children are smaller and lighter than European children, their shape (i.e. weight for height) and the ages at which peak height and weight increase are attained, are approximately the same. The data may form a basis for assessing the present state of growth and physique in Tanzania, but for the future more general standards will be required and some attempt should be made to investigate the possibility of using indices of muscle mass which are more pertinent to the physiological development of the child.

A Dislocation Mechanism for Cryogenic Relaxations in Crystalline Polymers

The experimental properties of the δc-relaxation observed in polyethylene, poly(oxymethylene), and poly(ethylene terephthalate) at about 50°K are reviewed. A mechanism is proposed involving the thermally activated redistribution of kinks along a discontinuous dislocation under an applied stress. The activation energy and relaxation intensity are discussed with reference to specific chain conformations in the dislocation. It is suggested that the kinked dislocations arise from external stresses transferred to the crystalline or ordered regions of the polymer possibly via tie molecules. These stresses are greatest in deformed material or material annealed under constraint and accounts for the increase in peak height observed in these specimens.

Effect of internal exposure by 90Sr and 131-I on respiratory 14CO2 patterns following 14C-glucose administration in mice.

Effects of internal irradiation by 90Sr and 131I were compared using 14C-glucose oxidation test in mice. Mice were injected with 2 μCi/g body weight of 90Sr or 5 μCi/capita of 131I for internal irradiation. At one day or 1, 3, 6, 9 weeks after injection of 90Sr and one or seven days after injection of 131I, the respiratory 14CO2 patterns of the animals were studied by continuous measurement of 14CO, and CO, in the exhaled air. The time course pattern of specific activity was obtained by calculating the ratios of the observed value of 14CO2 and CO2. The effect of internal exposure on respiratory 14CO2 were evaluated by the following parameters; 1) peak time, i. e., the time from injection to maximum specific activity, and 2) peak height, the maximum specific activity at peak time. In the control group, the value of specific activity of exhaled 14CO2 increased immediately after 14C-glucose administration, reached the maximum at 30 minutes and then gradually decreased. Internal irradiation with 90Sr caused a front shift, i. e., decrease in peak time with no appreciable change in peak height as compared with control. In the case of 131I, the respiratory pattern underwent an upper shift, i, e., increase in peak height with no change in peak time. To clarify the mechanism of the phenomena obtained by these internal emitters, the effect of some drugs on the change of respiratory 14CO2 pattern were studied. It was suggested that respiratory 14CO2 pattern analysis may serve as a useful tool in the comparative study of the effect of various internal emitters.