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71.
Alisha A. Etheredge Ei Ye Mon Kenroy Crawford Donald Hurtz Grace Choi Kristin Ashby 《Polycyclic Aromatic Compounds》2013,33(5):355-368
We have developed a preliminary method for the qualitative assessment of polycyclic aromatic hydrocarbon (PAH) tetrol metabolites in humans using serum albumin adducts. The method was used to investigate the presence of tetrol metabolites of PAHs released following acid hydrolysis of serum albumin-diol epoxide adducts. Liquid-liquid extraction and solid phase extraction were used for isolation and purification of the tetrol metabolites. Purified tetrols were derivatized to convert them to their trimethylsilyl derivatives and analyzed using gas chromatography/high resolution mass spectrometry. A total of 26 tetrol isomers were investigated, resulting in observation of the following 8 tetrols in 3 smoking and 7 non-smoking donors: 5-methylchrysene-1,2,3,4-anti-tetrol, benz(a)anthracene-1,2,3,4-anti-tetrol, benz(a)anthracene-1,2,3,4-syn-tetrol, benz(a)anthracene-8,9,10,11-anti-tetrol, (±)-benzo(a)pyrene-r-7,t-8,9,c-10-tetrahydrotetrol (BPTI-1), (±)-benzo(a)pyrene-r-7,t-8,c-9,t-10-tetrahydrotetrol (BPTII-1), (±)-benzo(a)pyrene-r-7,t-8,c-9,10-tetrahydrotetrol (BPTII-2), and (±)-benzo(a)pyrene-r-7,t-8,9,10-tetrahydrotetrol (BPTI-2). This preliminary work presents the first reported method for the assessment of PAH multi-analyte tetrol isomers extracted from serum albumin adducts in human donors. 相似文献
72.
The mechanical behavior of bulk cryomilled aluminum stabilized by diamantane nanoparticles is compared with that of bulk cryomilled commercial purity (CP) aluminum with no diamantane. Bulk cryomilled aluminum was prepared by consolidating the cryomilled aluminum powders via hot isostatic pressing followed by trap extrusion (high strain extrusion) at room temperature. The results revealed that, while the grain size of cryomilled CP aluminum (155 nm) was larger than that of cryomilled aluminum containing diamantane (68–95 nm), the strength of the former is higher than of the latter. This finding is explained in terms of the occurrence of nanoscale softening, which signifies a transition from conventional Hall–Petch behavior (strengthening with decreasing grain size) to inverse Hall–Petch behavior (softening with decreasing grain size). 相似文献
73.
The main objectives of this study were to improve the aqueous solubility and to modify in vitro dissolution profile of hydrophobic drug using self-emulsifying drug delivery systems (SEDDS). SEDDS were formulated using Capmul PG-12, Cremophor RH 40 and Tween 20 at different weight ratios and incorporated with Cinnarizine. The drug incorporation into pre-concentrate and drug solubility in phosphate buffer (pH 7.2) were investigated. In addition, the mean droplet size and drug release profile of the SEDDS were also determined. The drug incorporation was over 120?mg per 0.5?g pre-concentrate regardless of the composition of the formulations. The solubility of Cinnarizine in phosphate buffer (pH 7.2) was at least 1500 μM in the SEDDS. Formulations with only 10% w/w Capmul PG-12 were less than 20?nm in mean diameter while those produced with at least 20% w/w Capmul PG-12 were more than 100?nm regardless of the ratios of Cremophor RH 40 to Tween 20. SEDDS showed a significant increase of the mean percentage drug release than pure drug (p?0.0001). In general, the SEDDS with 30% w/w of Capmul PG-12 provided the greatest enhancement in drug solubility in phosphate buffer as well as rapid drug release despite forming larger droplets upon emulsification. The combination of Capmul PG-12, Tween 20 and Cremophor RH 40 can produce SEDDS which can be used as an alternative dosage form for poorly water soluble drug. 相似文献
74.
Metallic nanoparticles that support surface plasmons are potential building units for future nanophotonic circuits, metamaterials, high-density optical data storage, etc. Many of these applications require the ability to 'dial-up' the desired plasmonic resonance modes and frequencies with high precision. Here, we demonstrate a thermal reshaping route that can be used to tailor longitudinal plasmon resonance energies of gold nanorods almost continuously from ~800 to ~560 nm. The longitudinal plasmon resonance wavelength exhibits an exponential decay function of the thermal annealing time at a given temperature. This correlates with the transmission electron microscopy characterization (TEM) which showed that the nanorod aspect ratio decreases exponentially with time, accompanying a gradual shape transformation from rod to sphere. The exponential decay half-time decreases with increasing annealing temperatures, with a value of 1.43 × 10(5) s at 50?°C down to 0.02 × 10(5) s at 100?°C. Our experimental results show that the shape transformation could be attributed to desorption of silver ions and side facet-binding Ag-Br-CTA ligands, which therefore promote the side growth leading to nanorod fattening. Compared to other synthetic methodologies to tune plasmonics, our thermal reshaping approach presents a straightforward paradigm for precisely tailoring plasmon resonance energy with a single parameter. 相似文献
75.
Nan Ei Yu Sunao Kurimura Yoshiyuki Nomura Kenji Kitamura 《Materials Science and Engineering: B》2005,120(1-3):146-149
Periodically poled stoichiometric lithium tantalate was used for an efficient high-power coherent green light generation based on second-harmonic generation (SHG) using a Q-switched Nd:YVO4 laser. Achieved conversion efficiency was 69% that corresponds to SHG power density of 21.6 MW/cm2 at the maximum input fundamental peak power density of 31.5 MW/cm2. The SHG power fluctuation was less than 3.4% for 35 h, which was mainly caused by input power fluctuation of 2.6%. Obtained SHG powers of 4.4 and 3.4 W were sufficiently stable without spatial beam distortion at room temperature and a phase matching temperature adjustment was required precisely at high input power. 相似文献
76.
半连续式油脂脱臭工艺系统 总被引:1,自引:1,他引:0
连续式脱臭系统,如填料式脱臭塔、塔盘式脱臭塔和猛犸泵塔盘式脱臭塔采用本地和进口部件相结合。然而有中间排放塔盘的半连续式脱臭塔则是最复杂的,在精炼各种不同油品的过程中,如不同程度的氢化油、棕榈油、棕榈油中间分提物、可可脂类物质、代可可脂和液态棕榈油等,最少的油品污染和快速的批次变换是必要的,这里介绍我们从150t/d到300t/d的半连续式脱臭塔方面的经验。 相似文献
77.
To study the evolutionary relationships among the four living gymnosperm orders and the interfamilial relationships in each order, a set of 65 nuclear 18S rRNA sequences from ferns, gymnosperms, and angiosperms was analyzed using the neighbor-joining and maximum-parsimony methods. With Selaginella as the outgroup, the analysis strongly indicates that the seed plants form a monophyletic group with the ferns as a sister group. Within the seed plants the angiosperms are clearly a monophyletic group. Although the bootstrap support for the monophyly of the gymnosperm clade is moderate, the monophyly is further supported by its lack of angiosperm-specific indels. Within the gymnosperms there appear to be three monophyletic clades: Cycadales-Ginkgoales, Gnetales, and Coniferales. The cycad-ginkgo clade is the earliest gymnosperm lineage. Given the strong support for the sister group relationship between Gnetales and Coniferales, it is unlikely that Gnetales is a sister group of the angiosperms, contrary to the view of many plant taxonomists. Within Coniferales, Pinaceae is monophyletic and basal to the remaining conifer families, among which there are three monophyletic clades: Phyllocladaceae-Podocarpaceae, Araucariaceae, and Sciadopityaceae-Taxaceae-Cephalotaxaceae-Taxodiacea e-Cupressaceae. Within the latter clade, Sciadopityaceae may be an outgroup to the other four families. Among the angiosperms, no significant cluster at the level of subclass was found, but there was evidence that Nymphaeaceae branched off first. Within the remaining angiosperms, the monocots included in this study are nested and form a monophyletic group. This study attests to the utility of nuclear 18S rRNA sequences in addressing relationships among living gymnosperms. Considerable variation in substitution rates was observed among the ferns and seed plants. 相似文献
78.
Masami ANDO Anton MAKSIMENKO Tetsuya YUASA Eiko HASHIMOTO Katsuhito YAMASAKI Shu IHIHARA Hiroshi SUGIYAMA Tokiko ENDO LI Gang CHEN Zhihua Kazuyuki HYODO Ei UENO 《核技术(英文版)》2006,17(6):389-395
Duetal carcinoma in-situ (DCIS) has been visualized by 2D XDFI (X-ray dark-field imaging) and further by a 3D X-ray CT, and the data was acquired by the X-ray optics DEI (diffraction-enhanced imaging). A newly made al- gorithm was used for CT, Data of 900 projections with interval of 0.2 degrees were used. Ductus lactiferi, microcalci- fication in a 3D form have been clearly visible. The spatial resolution available was approximately 30 μm. 相似文献
79.
80.
Crid Yu Tinaung Maung Spanos C.J. Boning D.S. Chung J.E. Hua-Yu Liu Keh-Jeng Chang Bartelink D.J. 《Semiconductor Manufacturing, IEEE Transactions on》1995,8(2):150-159
Modern submicron processes are more sensitive to both random and systematic wafer-level process variation than ever before. Given the dimensional control limitations of new technologies, the amount of wafer-to-wafer and within wafer nonuniformity of many steps is becoming a significant fraction of the total error budget, which already includes the usual step-to-step allocations. However, a significant portion of the total observed variability is systematic in nature. Accordingly, particle defects may not continue to dominate parametric yield loss without improved understanding of parametric variations. In this paper, we demonstrate the use of short-loop electrical metrology to carefully characterize and decouple wafer-level variability of several critical processing steps. More specifically, we present our method and give results obtained from variability analyses for lithography critical dimension (CD) and inter-level dielectric (ILD) thickness control. Using statistically designed experiments and dedicated test structures, the main factors affecting dielectric thickness variability has been identified. The systematic variability from a wafer stepper has been extracted using a physically based statistical data filter. Once isolated, the deterministic variability can be modeled and controlled to enhance process and circuit design for manufacturability (DFM). We hope that in the future this work will be coupled with novel DFM-oriented CAD tools that encapsulate this information in a fashion that makes it useful to process and circuit designers 相似文献