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51.
Eisner Salamanca Yu-Hwa Pan Ying-Sui Sun Hao-Wen Hsueh Odontuya Dorj Wan-Ling Yao Jerry Chin-Yi Lin Nai-Chia Teng Ikki Watanabe Shinichi Abe Yi-Fan Wu Wei-Jen Chang 《International journal of molecular sciences》2022,23(3)
In vitro, in vivo, and clinical studies have shown how the physicochemical and biological properties of β-tricalcium phosphate (β-TCP) work in bone regeneration. This study aimed to improve the properties of β-TCP by achieving optimum surface and bulk β-TCP chemical/physical properties through the hydrothermal addition of magnesium (Mg) and to later establish the biocompatibility of β-TCP/Mg for bone grafting and tissue engineering treatments. Multiple in vitro and in vivo analyses were used to complete β-TCP/Mg physicochemical and biological characterization. The addition of MgO brought about a modest rise in the number of β-TCP surface particles, indicating improvements in alkaline phosphatase (ALP) activity on day 21 (p < 0.05) and in the WST-1assay on all days (p < 0.05), with a corresponding increase in the upregulation of ALP and bone sialoprotein. SEM analyses stated that the surfaces of the β-TCP particles were not altered after the addition of Mg. Micro-CT and histomorphometric analysis from rabbit calvaria critical defects resulted in β-TCP/Mg managing to reform more new bone than the control defects and β-TCP control at 2, 6, and 8 weeks (* p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001, and **** p ≤ 0.0001). The hydrothermal addition of MgO to the β-TCP surfaces ameliorated its biocompatibility without altering its surface roughness resulting from the elemental composition while enhancing cell viability and proliferation, inducing more bone regeneration by osteoconduction in vivo and osteoblastic differentiation in vitro. 相似文献
52.
The morphology of poly(phenylene sulfide), PPS, obtained as processed film has been studied using wide angle X-ray scattering (WAXS), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). A unique morphology has been identified in the original film. The spherulites are very small in size and possess a cylindrical symmetry with their lamellae oriented on the edge. In these processed PPS films, the a-axis of the lattice is preferentially aligned perpendicular to the film plane, while the b and c axes are predominantly in the film plane. In the PPS isothermally crystallized from the melted, original film, there is no such preferential orientation. Thermal analysis of the original and melt crystal-lized PPS shows that while the degree of crystallinity is about the same, the nature of the amorphous phase in the two materials is different. In the original film, we did not observe a heat capacity increment at a glass transition temperature by DSC, indicating that all of the amorphous phase belongs to the category of rigid amorphous phase. In the melt crystallized PPS, a distinct glass transition was seen, though only a portion of the amorphous phase becomes mobile at Tg. The differences in orientation and mobility of the amorphous phase in the original film compared to melt crystallized PPS are explained by the different thermal processing procedures used for the two materials. 相似文献
53.
Subramaniam Sathivel Peter J. Bechtel Jerry K. Babbitt Witoon Prinyawiwatkul Mary Patterson 《Journal of food science》2005,70(2):E57-E63
ABSTRACT: Arrowtooth flounder soluble protein powder (AFSP) and arrowtooth flounder insoluble protein powder (AFISP) were evaluated for their functional, nutritional, and rheological properties. AFSP and AFISP contained 80% and 79% protein and 5.9% and 14.9% fat, respectively. Yield of AFSP (8.6%) was less than AFISP (13.1%). AFSP and AFISP had desirable essential amino acid and mineral contents. Emulsion stability of AFSP was greater than AFISP. Fat and water absorptions (mL/g protein) were 5.2 and 1.8 for AFSP, respectively, and 3.3 and 4.2 for AFISP Mayonnaises made from AFSP had greater emulsion stability than mayonnaise made from AFISP. Mayonnaises from both AFSP and AFISP possessed pseudoplastic and viscoelastic characteristics. 相似文献
54.
Lipid metabolism was studied in rats fed diets containing corn oil, coconut oil, or medium-chain triglyceride (MCT), a glyceride
mixture containing fatty acids of 8 and 10 carbons in length. The ingestion of MCT-supplemented, cholesterolfree diets depressed
plasma and liver total lipids and cholesterol as compared with corn oil-supplemented diets. In rats fed cholesterol-containing
diets, plasma cholesterol levels were not influenced by dietary MCT, but liver cholesterol levels were significantly lower
than in animals fed corn oil. In vitro cholesterol synthesis from acetate-1-14C was lower in liver slices of rats that consumed MCT than in similar preparations from corn oil-fed rats. Studies of fatty
acid carboxyl labeling from acetate-1-14C and the conversion of palmitate-1-14C to C18 acids by liver slices showed that chain-lengthening activity is greater in the liver tissue of rats fed MCT than in the liver
of animals fed corn oil. The hepatic fatty acid desaturation mechanisms, evaluated by measuring the conversion of stearate-2-14C to oleate, was also enhanced by feeding MCT.
Adipose tissue of rats fed MCT converts acetate-1-14C to fatty acids at a much faster rate than does tissue from animals fed corn oil. Evidence is presented to show that the
enhanced incorporation of acetate into fatty acids by the adipose tissue of rats fed MCT represents de novo synthesis of fatty
acids and not chain-lengthening activity. Data are also presented on the fatty acid composition of plasma, liver, and adipose
tissue lipids of rats fed the different fats under study. 相似文献
55.
Weiqiang Li Jerry L. Jensen Walter B. Ayers Stephen M. Hubbard M. Reza Heidari 《Journal of Petroleum Science and Engineering》2009,68(3-4):180-186
Reservoir connectivity is often an important consideration for reservoir management. For example, connectivity controls waterflood sweep efficiency and it affects decisions concerning well placement and spacing. The uncertainty of sandbody distributions, however, can make interwell connectivity prediction extremely difficult. Percolation models are a useful tool to simulate sandbody connectivity behavior to estimate interwell connectivity.This study applies a percolation method to estimate interwell connectivity. Using results derived by Andrade, King, and others for fluid travel time between locations in a percolation model, we develop a method to estimate interwell connectivity. Four parameters are needed to use this approach: the net-to-gross ratio psand, the typical sandbody size, reservoir length and well spacing. To evaluate this new percolation method, the results are compared to results from geometrical models, Monte Carlo, and reservoir simulation.These methods were applied to estimate interwell connectivity for three non-communicating stratigraphic intervals in Monument Butte oil field, Utah. The results suggest that the percolation method can estimate the probability of interwell connectivity reliably for thin intervals for any values of psand, well spacing, and reservoir length. The geometrical model also performs well, but can only be applied in fields where the well spacing is less than one-half of the sandbody size.The proposed method requires that the reservoir interval for evaluation be sufficiently thin so that 2D percolation results can be applied. For thick intervals or heterogeneous sandbody distributions, the percolation method developed here is not suitable because it assumes thin layers. Future percolation research will be needed to adapt this new method to 3D cases. 相似文献
56.
57.
Jerry Wellington 《Canadian Journal of Science, Mathematics, & Technology Education》2013,13(3):313-314
Alsop, S., Bencze, L., & Pedretti, E. (Eds.). (2005). Analysing Exemplary Science Teaching. Maidenhead: Open University Press. ISBN: 0–335–21311–1 相似文献
58.
Geometric deformable models based on the level set method have become very popular in the last decade. To overcome an inherent
limitation in accuracy while maintaining computational efficiency, adaptive grid techniques using local grid refinement have
been developed for use with these models. This strategy, however, requires a very complex data structure, yields large numbers
of contour points, and is inconsistent with the implementation of topology-preserving geometric deformable models (TGDMs).
In this paper, we investigate the use of an alternative adaptive grid technique called the moving grid method with geometric
deformable models. In addition to the development of a consistent moving grid geometric deformable model framework, our main
contributions include the introduction of a new grid nondegeneracy constraint, the design of a new grid adaptation criterion,
and the development of novel numerical methods and an efficient implementation scheme. The overall method is simpler to implement
than using grid refinement, requiring no large, complex, hierarchical data structures. It also offers an extra benefit of
automatically reducing the number of contour vertices in the final results. After presenting the algorithm, we demonstrate
its performance using both simulated and real images.
This work was supported in part by NSF/ERC Grant CISST#9731748 and by NIH/NINDS Grant R01NS37747. 相似文献
59.
The mystery of the lack of a positive relationship between growth and urbanization in sub-Saharan Africa has been raised in
a number of studies. A recent paper by Barrios et al. (Journal of Urban Economics 60:357–371, 2006) provides a compelling explanation for why this occurs. Exploiting a new data source, they show how climate change, specifically
the reduction in rainfall, has driven people from the increasingly impoverished countryside to the city. They also show that
while this is an important factor explaining urbanization in sub-Saharan African countries it does not affect urbanization
elsewhere. Their explanation for this important difference is differences in the patterns of rainfall, as well as the composition
of soil in most sub-Saharan countries. In a word, geographical factors have dominated the unusual pattern observed in the
world’s most rapidly urbanizing continent. In this paper, we extend the work done by Barrios et al. to include more observations
and more detailed geographic variables. We first replicate their results and extend the number of observations to more recent
periods. Then we consider the effects of a range of specific country geographical characteristics, relying on data developed
by other researchers. After discussing our results, we focus on the implications of our findings for policy formulation, particularly
for sub-Saharan African countries. The results indicate that geographical circumstances place significantly more important
constraints on maximization processes. In other words, urbanization in these countries takes place in a profoundly “second-best”
world. We consider what this kind of context implies for the sequencing and implementation of economic reforms which would
allow for an urbanization process that would be more conducive to economic growth. 相似文献
60.