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The aim of this retrospective clinical study was to compare the longevity of cervical restorations between resin composite (RC) and glass ionomer (GI) and to investigate variables predictive of their outcome. The clinical performance of the two restorative materials in function was compared using the ratings of the modified United States Public Health Service (USPHS) criteria. A total of 479 cervical restorations were included in the study. Ninety-one already-replaced restorations were reviewed from dental records. The other 388 restorations still in function were evaluated according to the modified USPHS criteria by two investigators. Longevity and prognostic variables were analyzed with the Kaplan-Meier survival analysis and multivariate Cox proportional hazard model. The clinical performances of the two materials were evaluated according to the ratings of the USPHS criteria and compared using the Pearson chi-square test and Fisher exact test. The longevity was not significantly different between RC and GI (median survival time, 10.4 ± 0.7 and 11.5 ± 1.1 years, respectively). The main reasons for failure were loss of retention (82.2%) and secondary caries (17.8%). The longevity of cervical restoration was significantly influenced by tooth group and operator group (Wald test, p<0.05), while material, gender, presence or absence of systemic diseases, arch, and reason for treatment did not affect the longevity. Contrary to the longevity, the clinical performance of RC was superior to GI in the criteria of retention, marginal discoloration, and marginal adaptation, but similar in secondary caries, wear, and postoperative sensitivity. [ABSTRACT FROM AUTHOR]

In this paper, an LmC resonant converter is proposed for low output current ripple, and its steady-state analysis and design guidelines are investigated. In the LmC converter, the current stress of the output capacitors is reduced due to the inductive output filter, and the series resonant inductor is removed while maintaining the benefits of an LLC resonant converter such as zero-voltage switching and narrow switching frequency range. The mode analysis is described, and the steady-state characteristics are explored using the extended describing function. Based on the result, the design guidelines are suggested. A 240-W 24-V/10-A hardware prototype is built and tested to verify the analysis results and to evaluate the performance of the LmC resonant converter. [ABSTRACT FROM PUBLISHER]

Differences in electrochemical characteristics among Li-ion cells inevitably result in state-of-charge (SOC) imbalance when the existing voltage balancing technique is used. This paper presents a new approach based on a screening process for improved voltage/SOC balancing of a Li-ion series battery pack. Two kinds of screening processes, capacity screening and resistance screening, are implemented in an orderly manner. The capacity screening process matches open-circuit voltage (OCV)-SOC relation for achievement of voltage/SOC balancing. In the resistance screening process, pulse-type discharging/charging currents are applied to various SOC points to select the cells with similar voltage variance. Through two screening processes, the cells that have similar electrochemical characteristics are finally selected, and can be used for stable configuration of a Li-ion series battery pack. The proposed screening process has been validated by extensive experimental results and SOC estimation results based on extended Kalman filter. [ABSTRACT FROM AUTHOR]

Differences in electrochemical characteristics among Li-ion batteries result in erroneous state-of-charge (SOC)/capacity estimation and state-of-health (SOH) prediction when using the existing dual extended Kalman filter (DEKF) algorithm. This paper presents a complementary cooperation algorithm based on DEKF combined with pattern recognition as an application Hamming neural network to the identification of suitable battery model parameters for improved SOC/capacity estimation and SOH prediction. Two kinds of pattern such as discharging/charging voltage pattern (DCVP) and capacity pattern (CP) were measured, together with the battery parameters, as representative patterns. Through statistical analysis, the Hamming network is applied for identification of the representative DCVP and CP that most closely matche that of the arbitrary battery to be measured. The model parameters of the representative battery are then applied for SOC/capacity estimation and SOH prediction of the arbitrary battery using the DEKF. This avoids the need for repeated parameter measurement. [ABSTRACT FROM AUTHOR]

Background The non-essential amino acid,l-glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A2 (cPLA2) activity. cPLA2 has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined. Objective To investigate the effects of Gln on allergic bronchial inflammation and airway hyperresponsiveness (AHR), and to determine the possible action mechanisms of Gln in a murine model of asthma. Methods cPLA2 phosphorylation was assessed by immunoprecipitation and Western blotting. Smears of bronchoalveolar lavage cells were stained with Diff-Quik solution for differential cell counting. Airway levels of the proteins [T-helper type-1 (Th1) and Th2 cytokines, and mucin] were measured by ELISA. mRNA expression of cytokines was assessed by real-time RT-PCR. AHR was assessed as a change in airway resistance (RL). Histological studies were performed to assess the levels of mucin and pulmonary inflammation. Results Systemic Gln administration inhibited cPLA2 phosphorylation and its enzymatic activity in the lungs. Additionally, Gln effectively suppressed the key features of Th2-dependent asthmatic features, such as airway eosinophilia, mucus formation, and airway type 2 cytokine production, as well as late AHR. Conclusion Gln was found to be effective in the suppression of Th2-dependent phenotypes and late AHR, and this effect of Gln appeared to be at least partially attributable to its ability to suppress cLPA2 activity in the airway. Our results suggest that clinical use of Gln for patients with asthma may be beneficial. [ABSTRACT FROM AUTHOR]

Background: Dietary fats alter LDL and HDL cholesterol while serving as precursors of postprandial triacylglycerol-rich lipoproteins (TRLs). Objective: We hypothesized that the saturated fatty acid (SFA)- mediated increase and the polyunsaturated fatty acid (PUFA)-mediated decrease in endogenous lipoprotein cholesterol are promoted by postprandial TRLs. Design: We performed a 16-d crossover diet study to examine the effect of PUFA-rich [ratio of PUFAs to SFAs (P:S) = 2.0] and SFA-rich (P:S=0.25) diets on fasting and postprandial plasma lipid and lipoprotein-cholesterol concentrations in 16 normolipidemic subjects. Results: Fasting plasma cholesterol decreased significantly after a PUFA-rich diet because of a decrease in LDL (-12.3%; P < 0.05) and HDL (-3.8%; NS), but did not change after an SFA-rich diet. The appearance of postprandial TRLs in plasma at 4 h was linked to a significant lowering of both LDL(-7.4%) and HDL(-4.8%) after a PUFA-rich diet; no such effect was observed after the SFA-rich diet. At 7 h, LDL and HDL cholesterol returned to near fasting concentrations without postprandial TRL accumulation after a PUFA-rich diet but with a significant postprandial TRL accumulation after an SFA-rich diet. Thus, the in vivo postprandial clearance of cholesterol in LDL+HDLwas greater after a PUFA-rich diet than after an SFA-rich diet. The appearance of postprandial TRLs in plasma increased the cholesteryl ester transfer protein-mediated transfer of cholesteryl ester from LDL+HDL to TRLs in vitro without a significant influence from dietary fat. Conclusion: Dietary fat-mediated alterations in the rate of hepatic removal of postprandial TRLs, which carry cholesterol accepted from LDL+HDL via cholesteryl ester transfer protein in vivo, may contribute to the dietary fat-mediated change in endogenous lipoprotein cholesterol. [ABSTRACT FROM AUTHOR]

Background: Moderate alcohol consumption increases plasma HDL and lowers cardiovascular disease risk while transiently enhancing postprandial lipemia. Objective:We hypothesized that the alcohol-mediated increase in postprandial triacylglycerol-rich lipoproteins (TRLs) and their clearance elevate HDL cholesterol and reverse cholesterol transport. Design: We determined the effect in normolipidemic humans (n = 14) of postprandial lipemia produced 4 h after a test meal (M) or a test meal + 0.5 g alcohol/kg body wt (M+A) on postprandial changes in plasma lipids and on the balance of cholesterol between TRL and the cholesterol-rich LDL and HDL fractions (CRL) or red blood cells (RBCs) in fresh and incubated plasma or blood. Results: Postprandial lipemia after the M and M+A test meals caused a 56% and 89% increase in plasma triacylglycerol, a 30% and 74% increase in TRL cholesterol, and a 3.8% and 6.6% decrease in CRL cholesterol, respectively. In vitro reaction of endogenous lecithin:cholesterol acyltransferase (EC 2.3.1.43) and cholesteryl ester transfer proteins via incubation of fasting plasma samples and postprandial M and M+A plasma samples for 16 h increased TRL cholesterol by 22.8% (0.08 mmol/L), 32.6% (0.16 mmol/L), and 45.8% (0.28 mmol/L) in plasma and by 71.1% (0.27 mmol/L), 89.4% (0.45 mmol/L), and 112.5% (0.70 mmol/L) in RBC-enriched blood, respectively. After the in vitro lipolysis of TRL, the elevation of HDL cholesterol in postprandial M+A plasma, but not in postprandialMplasma, was significantly greater than in fasting plasma. Conclusion: The alcohol-mediated increase in postprandial TRL flux and the hepatic removal of postprandial TRL after the acceptance of cholesterol from CRL and cell membranes contribute to increased HDL cholesterol and enhancement of reverse cholesterol transport in humans. [ABSTRACT FROM AUTHOR]

Shrinkage in light curing resin composites is assumed to be directed toward the light source. However, the strong bond at the dentin-resin interface achieved by newer generation dentin bonding systems may affect the direction of polymerization shrinkage. In this study, various curing modes of adhesive resin simulating different bond qualities were applied to determine the extent of interfacial gap formation with a scanning electron microscope. We also measured the free surface depression with a profilometer. The direction of polymerization shrinkage was inferred from the ratio of the interfacial gap measurement at the floor to the free surface depression. Various curing modes used in this study include Group 1: light curing of resin composite without the bonding agent as the negative control; Group 2: simultaneous light curing of the bonding agent and resin composite; Group 3: start of the chemical cure of the dual-cured bonding agent before light curing the resin composite; Group 4: curing the light-initiated bonding agent before insertion and light curing of the resin composite. When the bonding agent was light cured prior to inserting the resin composite (Group 4), the free surface depression was the greatest and the interfacial gap smallest among those in all groups. Therefore, if a good bond between dentin and resin composite can be established, the shrinkage flow will be directed toward a center located near the bonded interface rather than toward the incident light , thus reducing detrimental shrinkage stress. [ABSTRACT FROM AUTHOR]

After polishing or glazing, slight color changes of machined porcelain restorations may be perceived, compared to the originally selected shade. This study compared the precision of the tristimulus colorimeter with the spectrophotometer to quantitatively measure the color changes of milled porcelain restorations after polishing or glazing and to evaluate the relationship between the color changes and the surface roughness. Ten two-millimeter thickness specimens of each shade were prepared from five shades of Vita Cerec Mark II porcelain blocks. Each specimen was ground with #220 grit SiC paper on an automatic polishing machine to simulate the surface roughness of milled restoration ground with 54 or 64 µm diamond grinding tools. To compare the precision of the spectrophotometer with the tristimulus colorimeter, CIE Lab* values of each specimen were measured and the coefficients of variation (CV) for each instrument computed. Ra values were also obtained using a Surface Analyzer. After verifying the precision of the tristimulus colorimeter, a second set of measurements were taken after the polishing or glazing procedure to quantitatively evaluate the effect of these procedures on the shade of the milled restorations. To evaluate the relationship between the color change and the surface roughness, a second set of Ra measurements were taken and the correlation between them analyzed. The tristimulus colorimeter measured the L* value more precisely than the spectrophotometer (p<0.05), but on the a* and b* color coordinates, it was not significantly superior to the spectrophotometer (p>0.05). The color difference values produced by polishing or glazing were greater than 2 ΔE units. After polishing and glazing, among the three coordinates examined, ΔL* was the most prominent determinant on ΔE*(ΔR²/polishing=0.9744 and ΔR²/glazing=0.9413), but Δa* and Δb* had little effect. There was no statistically significant correlation between the changes in surface roughness and color in either polishing (r=0.3555, p=0.0812) or glazing (r=-0.1570, p=0.4520). [ABSTRACT FROM AUTHOR]