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161.
162.
Analysis of different extracts of Satureja hortensis L. obtained with various solvents (by supercritical CO2 and by traditional extraction techniques) is presented in this study to identify and to determine the major constituents responsible for the antioxidant activity. The total polyphenol and total flavonoid contents of the extracts were determined by spectrophotometric method and no correlation was found with the antioxidant activites. HPLC was also used to measure two diterpenes as carnosol and carnosic acid in the extracts. Neither carnosol nor carnosic acid were identified. Individual antioxidants as rosmarinic and caffeic acids were identified and quantified with TLC‐densitometry method. Rosmarinic acid was found in higher amount than caffeic acid. The content of rosmarinic acid was also determined with HPLC. A good correlation coefficient of 0.85 was found between the antioxidant activity and amount of rosmarinic acid, which leads to the conclusion that rosmarinic acid is among the main antioxidant compounds of S. hortensis L. plant.  相似文献   
163.
We propose an algorithm for 3-D multiview deblurring using spatially variant point spread functions (PSFs). The algorithm is applied to multiview reconstruction of volumetric microscopy images. It includes registration and estimation of the PSFs using irregularly placed point markers (beads). We formulate multiview deblurring as an energy minimization problem subject to L1-regularization. Optimization is based on the regularized Lucy-Richardson algorithm, which we extend to deal with our more general model. The model parameters are chosen in a profound way by optimizing them on a realistic training set. We quantitatively and qualitatively compare with existing methods and show that our method provides better signal-to-noise ratio and increases the resolution of the reconstructed images.  相似文献   
164.
In cattle with foot diseases, application of a block on the healthy partner claw is a common method of pain relief. The aim of this study was to evaluate the effect of wooden claw blocks on locomotion characteristics and weight distribution in healthy (group C; n = 17) versus lame (group L; n = 17) cattle. Group L was further subdivided into group L1 (lameness score ≤3; n = 7) and group L2 (lameness score >3; n = 10). We performed lameness scoring using a numeric rating system and measured locomotion characteristics using 2 accelerometers (400 Hz; kinematic outcome = stance phase duration; kinetic outcomes = foot load and toe-off) and a 4-scale weighing platform (difference of mean weight distribution across the limbs; ?weight) before and after application of a claw block. We applied claw blocks to a randomly assigned lateral or medial claw of the fore or hindlimb in group C cows, and on the healthy partner claw in group L cows. Variables were expressed as differences across limbs. We used 1-way ANOVA to determine the differences between groups C and L and between groups L1 and L2 for ?weight after application of the claw block. We performed paired t tests to compare variables before and after application of the claw block in groups C and L. Group L scored higher on the numeric rating system than group C (mean ± SD, 3.40 ± 0.62 vs. 1.87 ± 0.28) and showed greater differences in relative stance phase duration (16.34 ± 10.78% vs. 2.13 ± 1.94%), foot load (9.68 ± 8.06 g vs. 3.26 ± 3.69 g), toe-off (3.91 ± 3.14 g vs. 0.78 ± 0.66 g), and ?weight (53.62 ± 28.85% vs. 8.52 ± 6.19%). In group C, we observed an increase of 12.17 percentage points in ?weight after block application, from 8.52 ± 6.19% to 20.69 ± 17.01%. Compared with the baseline, group L showed a decrease in numeric rating system score (2.88 ± 0.49 vs. 3.40 ± 0.62) and a decrease in differences between the limbs in relative stance phase duration (7.66 ± 9.96% vs. 16.34 ± 10.78%) and foot load (4.26 ± 4.14 g vs. 9.68 ± 8.06 g) after application of a claw block. Group L2 showed smaller ?weight after application of a claw block than group L1 (?7.8 ± 8.7% vs. 10.4 ± 7.6%). After block application in group L, we observed smaller differences across the limbs in variables measured to describe gait-cycle characteristics while walking, but no significant improvement while standing. We concluded that application of a claw block must be combined with other methods of pain relief, such as analgesic medication.  相似文献   
165.
The effect of wollastonite nanofibers (NW) on biological resistance of medium-density fiberboards (MDF) made from wood and chicken-feather fibers (CF) against Antrodia vaillantii was studied. NW content of 10 % and CF content of 5 and 10 %, based on the dry weight of wood fibers, were applied to the MDF matrix, giving a total of six different MDF mixing treatments. Mass loss values were measured roughly following the EN 113 specifications. The results showed that NW significantly decreased mass loss to a considerable extent in all mixing ratios, proving its potential to be used as a suitable preservative in wood-composite materials without environmental hazards. A CF content of 5 % showed improving effects on biological resistance, while CF of 10 % was too high and resulted in a weak MDF-matrix; eventually the biological resistance did not improve properly. NW ameliorated part of the undesirable effect of adding chicken feather fibers to the MDF-matrix. A significantly high correlation was found between mass loss versus water absorption (R 2 of 81 %), implying that the penetration of water and fungal hyphae can have rather similar patterns. It can be concluded that NW not only can be used to improve the biological resistance in wood-composite materials against fungi attack, but it can also reduce some of the undesirable properties of chicken feathers, thus providing a reliable and renewable resource for natural fibers to be used in the MDF manufacturing industry.  相似文献   
166.
The growth and ordering of C60 molecules on the WO2/W(110) surface have been studied by low-temperature scanning tunnelling microscopy and spectroscopy (STM and STS), low-energy electron diffraction (LEED), and density functional theory (DFT) calculations. The results indicate the growth of a well-ordered C60 layer on the WO2/W(110) surface in which the molecules form a close-packed hexagonal structure with a unit cell parameter equal to 0.95 nm. The nucleation of the C60 layer starts at the substrate’s inner step edges. Low-temperature STM of C60 molecules performed at 78 K demonstrates well-resolved molecular orbitals within individual molecules. In the C60 monolayer on the WO2/W(110) surface, the molecules are aligned in one direction due to intermolecular interaction, as shown by the ordered molecular orbitals of individual C60. STS data obtained from the C60 monolayer on the WO2/W(110) surface are in good agreement with DFT calculations.  相似文献   
167.
Poly(L-lactide) (PLLA) oligo-esters with α-hydroxyl-ω-alkyl (alkyl = −CH2−[CH2−CH2]m−CH3, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10) end groups were synthesized by ring-opening polymerization of L-lactide (L-LA) catalyzed by tin(II) 2-ethylhexanoate Sn(Oct)2 in the presence of aliphatic alcohols as initiators (HO−CH2−[CH2−CH2]m−CH3, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10). High yields (~ 62 to 71%) and M n(NMR) in the range of 2120–2450 Da (PLLA) were obtained. Effects of alkyl end groups on thermal properties of the oligo-esters were analyzed by DSC, TGA and SAXS. Glass transition temperature (T g) gradually decreases with increase in the percent of−CH2−[CH2−CH2]m−CH3 end group, as results alkyl end group provides most flexibility to PLLA. An important effect of alkyl end group on a double cold crystallization (T c1 and T c2) was observed, and is directly related with the segregation phase between alkyl end group and PLLA. TGA analysis revealed that PLLA oligo-esters are more thermally stable with docosyl (−C22H45) respect to the butyl (−C4H9) end group, probably is due to steric hindrance of the end group (docosyl respect to butyl) toward intermolecular and intramolecular transesterification. SAXS analysis showed that alkyl end group as docosyl restricted the growth of lamellae thickness (D) due to steric hindrance. Characterization of hydroxyl and alkyl end groups in the PLLA oligo-esters was determined by MALDI-TOF, GPC, FT-IR and 1 H and 13 C NMR.  相似文献   
168.
Looking at exhaust‐gas after‐treatment systems in its entirety leads to further improvement of emission control devices and to the accomplishment of future challenges such as lower legislative emission limits, new fuels, and more efficient engine concepts. This article provides an overview on the state‐of‐the art mobile exhaust‐gas after‐treatment devices. Current and future challenges are discussed in the light of present approaches such as hierarchical modeling reaching from DFT computations of molecular processes to CFD simulation of entire lines of exhaust‐gas cleaning devices, close‐to‐reality emission control test benches and aging procedures, on‐board diagnostics, and catalyst characterization at operating conditions and preferentially all length scales. In future, knowledge‐based robot‐controlled preparation and dynamic models coupled with information from real operation will significantly support research and development.  相似文献   
169.
The possibility of fabricating SiC ceramics using special wood-based materials has been shown in previous research. To form accurate SiC bodies from wood-based green templates, special shaping techniques are necessary to fulfill the requirements on the finished ceramic products. Due to the fact that wood-based green templates undergo shrinkage during carbonization, no suitable forming processes for the wood-based green templates have been presented so far. In this publication different raw materials and 3D shaping production processes and their influence on green body properties are described. It was possible to produce green bodies with a MOR higher than 15 N/mm² and a density in the range above 0.82 g/cm³. It is shown that reduction of resin content decreases the strength significantly and a reduction to 30 mass % resin content reduces the MOR of flat pressed panels to the defined limit. The extruded samples showed a significantly lower strength (mean 18.1 N/mm², standard deviation 8.6 N/mm²). Injection molding was not applied successfully. The findings show that shape pressing and extrusion were applied successfully, but the green body properties differed significantly from the results achieved by flat pressing.  相似文献   
170.
This study presents a nanocomposite manufacturing route starting from non‐functionalized nanosilica and SAN surface modification via “grafting from” ATRP up to processing of transparent polycarbonate and glycol modified poly(ethylene terephthalate) nanocomposites. Synthesis limitations of low molecular weight graft SAN derived from “classical” ATRP are overcome by employment of the emerging ARGET ATRP. Mechanical investigations of polycarbonate and glycol modified poly(ethylene terephthalate) nanocomposites present up to 80% enhancement of creep performance and additionally 70% enhancement against wear abrasion for glycol modified poly(ethylene terephthalate) nanocomposites. Strength and tensile modulus are only moderately influenced by the addition of nanoparticles. Morphological studies confirm that the present modification route is able to create uniform dispersions of single particles and small particle aggregates in polymer matrices.

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