High performance liquid chromatographic separation of diacylglycerol acetates to quantitate disaturated species of lung phosphatidylcholine

A high-performance liquid chromatographic (HPLC) separation of diacylglycerol acetates to quantitatite disaturated species of lung phosphatidylcholine (PC) was studied. The diacylglycerol acetates were applied on a reversed phase column, eluted by an isocratic solvent, acetonitrile/isopropanol/water (35:15:1, v/v/v) at a flow rate of 1 ml/min, and detected by differential refractometry (RI). This isocratic HPLC method was useful to separate disaturated species from the others of lung PC. The quantitative analysis of the molecular species separated by HPLC was studied by RI detection. Chroamtograms obtained by RI detection and radioactivity determination of diacylglycerol [³H]acetates prepared by [³H]acetic anhydride were almost identical. The RI detector responsed in the same degree for different, authentic standards of diacylglycerol acetates. The detection limit with RI detection was about 30 nmoles. Molecular species of PCs from human lung and carcinoma tissues were analyzed by this HPLC method. The contents of disaturated species were very similar to those reported previously. These results indicate that RI detection is very useful in the nmole range for the quantitative analysis among the molecular species containing disaturated species.     

Microscopical imaging of hydroxyapatite/mica composite and packed hydroxyapatite structure--an atomic force microscopy investigation

A focus on the importance of leisure in the development of student nurses has been neglected in the 1990s. This study considers 444 prospective nurses on conventional, diploma and degree courses in two areas of England. It examines their activities associated with socializing, their social support networks and their use of clubs, sports and hobbies before entering nursing. It is evident that students enter nurse training with a wide variety of leisure experiences. Changing recruitment patterns and the structure of nurse training has an effect on the leisure needs of prospective nurses which must be addressed.     

Characterization of Silicon Carbide–Silicon Nitride Composite Ultrafine Particles Synthesized Using a CO2 Laser by Silicon-29 Magic Angle Spinning NMR and ESR

The structure of silicon carbide–silicon nitride (SiC–Si₃N₄) composite particles synthesized using a CO₂ laser was studied by magic angle spinning nuclear magnetic resonance (MAS-NMR) and electron spin resonance (ESR). The structure around Si atoms changed by introducing N. C atoms around Si were substituted by N atoms, and N-rich configurations around Si atoms increased stepwise as the N content increased. The low N content composite particles consisted of mainly SiC phase containing dissolved N. N atoms were partly present in β-SiC microcrystal and partly in the grain boundary layer in the particle. N atoms were tetrahedrally surrounded by four Si atoms in β-SiC microcrystal and were trivalent state bonded to three Si atoms in the grain boundary layer. The high N content particles consisted of SiC, Si₃N₄, and amorphous phases, whose amount depended on N content.     

Photoelectrochemical energy conversion system modeled on the photosynthetic process

Photo-excitable electrodes were prepared by incorporating magnesium chlorophyll (MgChl) or manganese chlorophyll (MnChl) into the thin layer of such liquid cyrstals as N-(p-methoxybenzylidene)-p-butylaniline (MBBA) and 4′-heptyl-4-cyanobiphenyl (HCB), being attached to the platinum surface. The MgChl—MBBA electrode gave the positive photo-induced potential shift in an acidic solution. In sharp contrast, the negative photo-induced potential shift was developed by the MnChl—HCB electrode in an alkaline solution. The involvement of a liquid crystal prominently enhanced the photo-response of the immobilized chlorophylls. The photoelectrochemical energy conversion system modeled on the photosynthetic process was assembled by employing the MgChl—MBBA and the MnChl—HCB electrodes as a cathode and an anode, respectively. The photocurrent derived from the system was concluded to result from the decomposition of water, since an evidence for the molecular oxygen evolution at the MnChl—HCB electrode was obtained. Furthermore, the incorporation of β-carotene was found to markedly enhance the stability of the MnChl—HCB electrode.     

Decomposition of chlorofluorocarbons on TiO2ZrO2

The decomposition of chlorofluorocarbons (CFCs) in the presence of water was examined over a variety of solid acid catalysts. The TiO₂ZrO₂ catalyst was found to have the highest activity and longest life among the catalysts examined. The activity of the TiO₂ZrO₂ catalysts depended upon the content of TiO₂. At the contents of TiO₂ from 58 to 90 mole%, the TiO₂ZrO₂ catalysts exhibited high activity, and these catalysts were proven to contain TiZrO₄ crystal. From the study of the XRD peak intensity of the TiZrO₄ crystal, it was highest on the TZ-58 which contained 58 mole% of TiO₂, and decreased with increasing the content of TiO₂. Furthermore, the conversion of CFC113 measured at 673 K was highest at TZ-58, and decreased gradually with increasing TiO₂ content. Therefore, the TiZrO₄ crystal influences the activity of decomposition of CFC113. However, the TiO₂ZrO₂ catalyst was gradually deactivated during the reaction due to the elimination of titanium atoms. A good relationship was found between the activity on TiO₂ZrO₂ catalyst and bond energy of CCl in the compounds of chlorofluorocarbons and hydrochlorocarbons, suggesting that the rate controlling step was the cleavage of CCl bond.     

Sudden death of adults in Japan

Epidemiological features, risk factors and preventive methods of sudden death (SD) derived from studies the authors have performed since 1987 together with colleagues in Niigata University School of Medicine were reviewed. When SD was defined as death occurring within 24 hours of the onset of symptoms, the annual incidence was 145/100,000 for people aged 15 years and older in Niigata Prefecture. The incidence increased sharply along with the advance of age, while the proportion of SD to natural death due to circulatory diseases was higher in younger people. Though diseases of the circulatory system made up approximately 90 percent of all causes of death, SD due to ischemic heart disease was less frequent in Japan than in western countries. SD showed various patterns in seasonal and "within-a-day" occurrences according to sex, age and cause of death. The months of the highest SD occurrence differed by occupation and matched the busiest work periods. A decrease in sleeping hours and mental stress experienced during the preceding week were related to the occurrence of both sudden death and non-fatal acute myocardial infarction. People having structural circulatory diseases were shown to be predisposed to SD when stress occurred, because fatal arrhythmia is easily induced by the above factors in such people. Health examinations were shown to have preventive effects, though limited, against SD. Differences in the resuscitated rates in cases where a witness was present and where one was not indicates that educating people about correct resuscitation methods is important to minimizing SD.     

Hot-water treatment of sol–gel derived SiO2–TiO2 microparticles and application to electrophoretic deposition for thick films

SiO₂–TiO₂ spherical microparticles of about 0.7 μm in diameter were prepared by the sol–gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 °C. From the changes in the concentration of I₂ photocatalytically generated from KI aqueous solution, the activity of the SiO₂–TiO₂ microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO₂–TiO₂ microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 μm with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity.     

Effects of water chemistry and potential distribution on electrochemical corrosion potential measurements in 553 K pure water

The effects of water chemistry distribution on the potential of a reference electrode and of the potential distribution on the measured potential should be known qualitatively to obtain accurate electrochemical corrosion potential (ECP) data in BWRs. First, the effects of oxygen on a platinum reference electrode were studied in 553 K pure water containing dissolved hydrogen (DH) concentration of 26–105 μg kg^?1 (ppb). The platinum electrode worked in the same way as the theoretical hydrogen electrode under the condition that the molar ratio of DH to dissolved oxygen (DO) was more than 10 and that DO was less than 100 ppb. Second, the effects of potential distribution on the measured potential were studied by using the ECP measurement part without platinum deposition on the surfaces connected to another ECP measurement part with platinum deposition on the surfaces in 553 K pure water containing 100–130 ppb of DH or 100–130 ppb of DH plus 400 ppb of hydrogen peroxide. Measured potentials for each ECP measurement part were in good agreement with literature data for each surface condition. The lead wire connecting point did not affect the measured potential. Potential should be measured at the nearest point from the reference electrode in which case it will be not affected by either the potential distribution or the connection point of the lead wire in pure water.     

Determination of emotional content of video clips by low-level audiovisual features

Affective analysis of video content has greatly increased the possibilities of the way we perceive and deal with media. Different kinds of strategies have been tried, but results are still opened to improvements. Most of the problems come from the lack of standardized test set and real affective models. In order to cope with these issues, in this paper we describe the results of our work on the determination of affective models for evaluation of video clips using audiovisual low-level features. The affective models were developed following two classes of psychological theories of affect: categorial and dimensional. The affective models were created from real data, acquired through a series of user experiments. They reflect the affective state of a viewer after watching a certain scene from a movie. We evaluate the detection of Pleasure, Arousal and Dominance coefficients as well as the detection rate of six affective categories. For this end, two Bayesian network topologies are used, a Hidden Markov Model and an Autoregressive Hidden Markov Model. The measurements were done using audio-only models, video-only models and fused models. Fusion is done using two different methods, a Decision Level Fusion and Feature Level Fusion. All tests were conducted using localized affective models, both categorial and dimensional. Results are presented in terms of detection rate and accuracy for affective families, affective dimensions and probabilistic networks. Arousal was the best detected dimension, followed by dominance and pleasure.