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Objectives: This study investigated the antibacterial, cytotoxicity, and mechanical properties of a dental adhesive modified with quaternary ammonium monomer ((2-acryloyloxyethyl)dimethyldodecylammonium bromide) and cross-linker (bis(2-acryloyloxyethyl)methyldodecylammonium bromide). Materials and methods: Monomer (M), cross-linker (C), or a combination of these (M + C) were incorporated into adhesive Adper Single Bond Plus (SB) in 5, 10, or 25% (as wt%). A colony-forming unit and MTT assays were used to evaluate antibacterial properties against Streptococcus mutans and cell viability. Resin-dentin beams (0.9 ± 0.1 mm2) were evaluated for micro-tensile bond strength (μTBS) after 24 h, 6 months, and 3 years. Hourglass specimens were evaluated for ultimate tensile strength (UTS) after 24 h, 1 week, and 6 months. Micro-hardness measurements after softening in ethanol were taken as an indirect assessment of the polymer cross-linking density. Kruskal-Wallis, one-way ANOVA, two-way ANOVA, and Student's t test were used for analysis of the antibacterial, cytotoxicity, μTBS, UTS, and hardness data, all with a significance level of p < 0.05. Results: 10%M and 25%M demonstrated a significant reduction in S. mutans relative to SB (p < 0.001). No differences in cytotoxicity were detected for any of the groups. After 6 months, no changes in μTBS were shown for any of the groups. After 3 years, all groups evidenced a significant decrease in μTBS (p < 0.05) except 5%M, 5%C, and 5%M + 5%C. All groups demonstrated either stable or significantly increased UTS after 6 months. Except for the cross-linker groups, a significant decrease in micro-hardness was shown for all groups after softening in ethanol (p < 0.05). Conclusions: A 5–10% of monomer may render the resin antibacterial without a compromise to its mechanical and bonding properties. Clinical relevance: Biomodification of a resin adhesive with an antibacterial monomer and cross-linker may help improve the life span of adhesive restorations. [ABSTRACT FROM AUTHOR]

Magnetic mesoporous carbon composites incorporating hydrophilic metallic nanoparticles were synthesized from resol, ZrO(NO), ferric acetylacetonate, and triblock copolymer F127. The method involves a multi-component co-assembly strategy associated with direct carbonization. The resulting carbon material is shown to be useful as a metal oxide affinity chromatography (MOAC) material for enrichment of phosphopeptides owing to its large mesoporous (4.8 nm) surface area (442 m g), large pore volume (0.37 cm g) and excellent hydrophilicity. The metallic iron and ferric oxide particles modified on the mesoporous carbon exert a magnetic force and, in combination with the metallic zirconia, is a viable MOAC material for enrichment of low-abundance phosphopeptides. Because of metal chelation between metallic nanoparticles and the phosphate groups of phosphopeptides, the zirconia/magnetic mesoporous carbon displays high selectivity even at a phosphopeptide/nonphosphopeptide molar ratio of 1:500. As little as 1.5 fmol of phosphopeptides become detectable. The MOAC was successfully applied to the identification by MALDI-TOF MS of phosphopeptides in human serum and nonfat milk. [ABSTRACT FROM AUTHOR]

For a series plug-in hybrid electric vehicle, higher working efficiency can be achieved by the drive system with two small motors in parallel than that with one big motor alone. However, the overly complex structure will inevitably lead to a substantial increase in the development cost. To improve the system price-performance ratio, a new kind of series-parallel hybrid system evolved from the series plug-in hybrid system is designed. According to the technical parameters of the selected components, the system model is established, and the vehicle dynamic property and pure electric drive economy are evaluated. Based on the dynamic programming, the energy management strategy for the drive system under the city driving cycle is developed, and the superiority validation of the system is completed. For the studied vehicle driven by the designed series-parallel plug-in hybrid system, compared with the one driven by the described series plug-in hybrid system, the dynamic property is significantly improved because of the multi-power coupling, and the fuel consumption is reduced by 11.4% with 10 city driving cycles. In a word, with the flexible configuration of the designed hybrid system and the optimized control strategy of the energy management, the vehicle performance can be obviously improved. [ABSTRACT FROM AUTHOR]

We developed a simple and rapid analysis method for the determination of four amphetamines in human whole blood and urine using gas chromatography-mass spectrometry (GC-MS). During the course of sample preparation, the evaporation process was found to be the weak point for amphetamine and methamphetamine analysis. Liquid-liquid extraction in this study was conducted without the evaporation step, and the upper solvent layer was injected directly without derivatization, which effectively prevented the volatile amphetamines from vanishing during evaporation and guaranteed the linearity of the calibration curves. This method showed good selectivity, precision, and accuracy, and at the same time was simple and fast. The limits of detection were 5 ng/ml. As an application of this study, a whole blood sample and urine sample from a drug abuse suspect were analyzed. This method may be able to meet the need for rapid and accurate confirmation of positive immunoassay results as well as quantification in clinical and forensic toxicological cases. To our knowledge, no forensic toxicologists have noted that such a basic and simple method, without evaporation or derivatization, is useful for routine analysis of amphetamines using GC-MS. [ABSTRACT FROM AUTHOR]