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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]

The most common and challenging issues in image recognition are scene character recognition from the street view image, and the scene character consists of both text and number. Recently, the researchers were introduced a lot of scene character recognition methods, but the performance of the methods often degraded due to complexity. So, we proposed the improved firefly algorithm for local trapping problem (IFLT) utilizing convolutional neural network (CNN) for the extraction of features from the scene character. The IFLT approach is the improved version of the firefly optimization algorithm to solve local trapping problems. During feature extraction, the hyperparameters on CNN are tuned with the help of the IFLT approach. The alignment and multilayer perceptron layers are used on CNN. Subsequently, the support vector machine approach is used to classify the relevant class of scene characters from the street view image. Experimentally, we use six scene character dataset SVHN, ISN, IIIT5K-words, SVT, ICDAR 2003, and ICDAR 2013 dataset. The performance of the proposed IFLT approach is evaluated with standard deviation, mean, average computational time, and most excellent minimum (MEmin) parameters. The experimental results demonstrate that the proposed IFLT-CNN is well suitable for scene character recognition. [ABSTRACT FROM AUTHOR]

A type of carbonate-hosted lead-zinc (Pb-Zn) ore deposits, known as Mississippi Valley Type (MVT) deposits, constitutes an important category of lead-zinc ore deposits. Previous studies proposed a fluid-mixing model to account for metal precipitation mechanism of the MVT ore deposits, in which fluids with metal-chloride complexes happen to mix with fluids with reduced sulfur, producing metal sulfide deposition. In this hypothesis, however, the detailed chemical kinetic process of mixing reactions, and especially the controlling factors on the metal precipitation are not yet clearly stated. In this paper, a series of mixing experiments under ambient temperature and pressure conditions were conducted to simulate the fluid mixing process, by titrating the metal-chloride solutions, doping with or without dolomite, and using NaHS solution. Experimental results, combined with the thermodynamic calculations, suggest that H2S, rather than HS− or S2−, dominated the reactions of Pb and/or Zn precipitation during the fluid mixing process, in which metal precipitation was influenced by the stability of metal complexes and the pH. Given the constant concentrations of metal and total S in fluids, the pH was a primary factor controlling the Pb and/or Zn metal precipitation. This is because neutralizing or neutralized processes for the ore-forming fluids can cause instabilities of Pb and/or Zn chloride complexes and re-distribution of sulfur species, and thus can facilitate the hydrolysis of Pb and Zn ions and precipitation of sulfides. Therefore, a weakly acidic to neutral fluid environment is most favorable for the precipitation of Pb and Zn sulfides associated with the carbonate-hosted Pb-Zn deposits. [ABSTRACT FROM AUTHOR]

The Langdu skarn copper deposit in the Zhongdian area, Yunnan Province, China, has an average Cu grade of 6.49 %. The deposit is related to a porphyry intrusion (~216 Ma), which was emplaced in the Upper Triassic sedimentary rocks of the Tumugou and Qugasi Formations. At the Langdu skarn copper deposit, carbon and oxygen isotope ratios of fresh limestones (δO = 3.0-5.6 ‰ relative to V-SMOW; δC = 24.5-25.7 ‰ relative to PDB) and partly altered limestones (δO = 27-7.2 to −1.9 ‰; δC = 11.8-15.2 ‰) indicated that the deposit was a typical marine carbonate source. Oxygen and carbon isotope values for calcites formed at different hydrothermal stages are −9.1 to 0.2 and 10.1-16.3 ‰, respectively. Moreover, the carbon-oxygen isotopic composition of an ore-forming fluid (δO = 5.0-9.5 ‰, δC = −7.3 to −5.3 ‰) suggested the presence of magmatic water, which most likely came from the differentiation or melting of a homologous magma chamber. The deposition of Calcite I may arise from metasomatism in an open system with a progressively decreasing temperature. Later, the minerals chalcopyrite, pyrrhotite, quartz and Calcite II were precipitated due to immiscibility. Water-rock interaction could potentially be responsible for Calcite III precipitation in the post-ore stage. [ABSTRACT FROM AUTHOR]

Purpose: The distribution and speciation of mercury in surface water of East River, Guangdong province, China were investigated. Methods: All told 63 water samples were collected during a bi-weekly sampling campaign from July 15th to 26th, 2009. Results: Total mercury (THg) concentrations in water samples ranged from 11 to 49 ng/L. Maximum levels of THg were measured in the lower reaches of East River, where it passes through a major industrial area adjacent to Dongguang city. Higher ratios of dissolved mercury (THg (aq)) in proportion to THg were restricted to the downstream section of East River. Concentrations of the minor constituent methyl mercury varied in the range from 0.08 to 0.21 ng/L. On average, methyl mercury made up 0.8% and 0.56% of THg (aq) and THg, respectively. Dissolved species dominated the speciation of methyl mercury in proportions up to 81%, which may imply that methyl mercury is largely produced in situ within the river water. Environmental factors (such as water temperature, dissolved oxygen, etc.) are regarded to play an important role in Hg methylation processes were monitored and assessed. Conclusions: In an international perspective, East River must be classified as a polluted river with considerably sources within its industrial areas. The THg (aq) and particle mercury fluxes to the Pearl River Estuary by East River run-off were estimated to be 0.31 ± 0.11 and 0.17 ± 0.13 t/year, respectively. Hence, in total nearly 0.5 t Hg is annually released to the sea from the East River tributary. [ABSTRACT FROM AUTHOR]

Image super-resolution reconstruction is an effective method to improve image resolution, but most reconstruction methods rely on the clear low resolution images ignoring the blurred images which are also effective observations of the scene. Aiming at the problem, a super-resolution reconstruction (SRR) method via multi-frame defocused images is proposed. Firstly, according to the image degraded model, we establish the cost function of the point spread function (PSF) and utilize the particle swarm optimization algorithm to estimate it. Then, based on the multi-frame defocused images and PSFs, a joint reconstruction model is established to realize SRR by compressive sensing (CS) theory. In the CS framework, only the interpolated version of the low-resolution image is used for training purpose and the K-Singular Value Decomposition method is used for dictionary training. In addition, to solve the edge effect problem, an internal blur matrix is constructed according to the image blurring process, and a weight coefficient is introduced in the patch splicing process. Experiments show that the proposed algorithm can accurately estimate the defocused image PSF and achieve a good reconstruction effect. [ABSTRACT FROM AUTHOR]