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31.
Herken EN Kocamaz E Kucukatay MB Vural H Demirin H Kucukatay V 《Biological trace element research》2008,123(1-3):202-210
A noticeable effect of sulfite treatment was observed on the plasma ceruloplasmin ferroxidase activity of rats with normal sulfite oxidase activity when compared to normal controls. The plasma levels of selenium, iron, and zinc were unaffected by sulfite in normal and sulfite oxidase (SOX)-deficient rats. While plasma level of Mn was decreasing, plasma Cu level increased in SOX-deficient rats. Treating SOX-deficient groups with sulfite did not alter plasma level of Mn but made plasma level of Cu back to its normal level. This is the first evidence that Cu and Mn status were affected in experimental sulfite oxidase deficiency induced by low molybdenum diet with tungsten addition deserving further research to determine the underlying mechanisms of these observations in experimental sulfite oxidase deficiency. 相似文献
32.
Tissue engineering essentially refers to technology for growing new human tissue and is distinct from regenerative medicine. Currently, pieces of skin are already being fabricated for clinical use and many other tissue types may be fabricated in the future.Tissue engineering was first defined in 1987 by the United States National Science Foundation which critically discussed the future targets of bioengineering research and its consequences. The principles of tissue engineering are to initiate cell cultures in vitro, grow them on scaffolds in situ and transplant the composite into a recipient in vivo. From the beginning, scaffolds have been necessary in tissue engineering applications. Regardless, the latest technology has redirected established approaches by omitting scaffolds. Currently, scientists from diverse research institutes are engineering skin without scaffolds. Due to their advantageous properties, stem cells have robustly transformed the tissue engineering field as part of an engineered bilayered skin substitute that will later be discussed in detail. Additionally, utilizing biomaterials or skin replacement products in skin tissue engineering as strategy to successfully direct cell proliferation and differentiation as well as to optimize the safety of handling during grafting is beneficial. This approach has also led to the cells’ application in developing the novel skin substitute that will be briefly explained in this review. 相似文献
33.
Due to the complicated physiological structure of soft biological tissues, stresses can only be measured after the specimen
has been stretched to many times of its related length. Therefore, the classical constitutive equations of finite elasticity
developed for vulcanized, rubbery materials and the linear theories developed for most engineering materials cannot be applied
to soft tissues which are highly elastic in nature.
In this article, utilizing a mechanical model developed by Demiray for soft tissues, a class of finite deformations of some
tissues is studied and the results are compared with experiment and the existing literature. These problems are the simultaneous
extension and twisting of a circular cylindrical bar, the bending of a rectangular block, and the pure shear of a rectangular
prism. It is believed that solutions to these problems may find some applications in plastic surgery.
Most of this work was done while one of the authors (H. D.) was visiting McMaster University (Hamilton, Ontario) during summer
1980 and supported through NSERC Grant 4364 and the other (M.L.) was Professor of Engn. Mechs. there. 相似文献
34.
Hilmi Demiray 《Bulletin of mathematical biology》1997,59(5):993-1012
In the present work, we study the propagation of solitary waves in a prestressed thick walled elastic tube filled with an
incompressible inviscid fluid. In order to include the geometric dispersion in the analysis the wall inertia and shear deformation
effects are taken into account for the inner pressure-cross-sectional area relation. Using the reductive perturbation technique,
the propagation of weakly non-linear waves in the long-wave approximation is examined. It is shown that, contrary to thin
tube theories, the present approach makes it possible to have solitary waves even for a Mooney-Rivlin (M-R) material. Due
to dependence of the coefficients of the governing Korteweg-deVries equation on initial deformation, the solution profile
changes with inner pressure and the axial stretch. The variation of wave profiles for a class of elastic materals are depicted
in graphical forms. As might be seen from these illustrations, with increasing thickness ratio, the profile of solitary wave
is steepened for a M-R material but it is broadened for biological tissues. 相似文献
35.
Theoretical note: tests of synergy in sweetener mixtures 总被引:3,自引:3,他引:0
Some methods for examining the additivity of sweeteners, and their synergy
in mixtures depend upon setting component concentrations on the basis of
sweetness equivalence, usually to a sucrose reference. These methods may
under- or over-predict the sweetness of a mixture, leading to spurious
claims of synergy or mixture suppression. This paper points out one problem
with one such popular method, in that the method can lead to a conclusion
that a substance would synergize with itself. To the extent that
self-synergy is an illogical conclusion for a mixture comparison, such a
method should be avoided in tests of synergy. The sweetness equivalence
approach is contrasted with a simpler approach based on concentrations that
does not lead to conclusions of self- synergy.
相似文献
36.
Yuejun Zhen Jie Qian Kara Follmann Tina Hayward Thomas Nilsson Michael Dahn Yasmin Hilmi Alicia G. Hamer Jonathan P. Hosler Shelagh Ferguson-Miller 《Protein expression and purification》1998,13(3):326-336
Theaa3-type cytochromecoxidase ofRhodobacter sphaeroideshas been overexpressed up to seven fold over that in wild-type strains by engineering a multicopy plasmid with all the required oxidase genes and by establishing optimum growth conditions. The two operons containing the three structural genes and two assembly genes for cytochromecoxidase were ligated into a pUC19 vector and reintroduced into several oxidase-deletedR. sphaeroidesstrains. Under conditions of relatively high pH and maximal aeration, high levels of expression were observed. A smaller expression vector, pBBR1MCS, and a fructose promoter (fruP)5were found not to enhance cytochromecoxidase expression inR. sphaeroides.An improved cytochromecoxidase purification protocol is reported, which combines histidine elution from a nickel affinity column and anion-exchange chromatography, and results in a higher yield and purity than previously obtained. 相似文献
37.
Hilal Arikoglu Hulya Ozdemir Dudu Erkoc Kaya Suleyman Hilmi Ipekci Ahmet Arslan Seyit Ali Kayis Mustafa Sait Gonen 《Gene》2014
Adiponectin, an adipose tissue specific protein encoded by the Adiponectin gene, modulates insulin sensitivity and plays an important role in regulating energy homeostasis. Many studies have shown that single nucleotide polymorphisms (SNPs) in the Adiponectin gene are associated with low plasma Adiponectin levels, insulin resistance and an increased risk of type 2 diabetes mellitus. The aim of the present study was to evaluate the contribution of the Adiponectin gene polymorphisms in genetic background of type 2 diabetes in a Turkish population. In total, 169 unrelated and non-obese diabetic patients and 119 age- and BMI-matched non-diabetic individuals with no family history of diabetes were enrolled in this study. We detected a significant association between type 2 diabetes and two SNPs: SNP − 11391G > A, which is located in the promoter region of the Adiponectin gene, and SNP + 276G > T, which is found in intron 2 of the gene (P < 0.05). The silence SNP G15G (+ 45T > G) in exon 1 and SNP + 349A > G in intron 2 also showed a weak association with type 2 diabetes (P = 0.06 and P = 0.07, respectively), while SNPs − 3971A > G in intron 1 and Y111H, R112C and H241P in exon 3 showed no association (P > 0.05). In conclusion, these findings suggest that Adiponectin gene polymorphisms might be effective on susceptibility for type 2 diabetes development which emerged from the interactions between multiple genes, variants and environmental factors. 相似文献
38.
39.
Sevtap Savas Laurent Briollais Irada Ibrahim-zada Hamdi Jarjanazi Yun Hee Choi Mireia Musquera Neil Fleshner Vasundara Venkateswaran Hilmi Ozcelik 《PloS one》2010,5(9)
Epidemiological studies have suggested an association between selenium intake and protection from a variety of cancer. Considering this clinical importance of selenium, we aimed to identify the genes associated with resistance to selenium treatment. We have applied a previous methodology developed by our group, which is based on the genetic and pharmacological data publicly available for the NCI60 cancer cell line panel. In short, we have categorized the NCI60 cell lines as selenium resistant and sensitive based on their growth inhibition (GI50) data. Then, we have utilized the Affymetrix 125K SNP chip data available and carried out a genome-wide case-control association study for the selenium sensitive and resistant NCI60 cell lines. Our results showed statistically significant association of four SNPs in 5q33–34, 10q11.2, 10q22.3 and 14q13.1 with selenium resistance. These SNPs were located in introns of the genes encoding for a kinase-scaffolding protein (AKAP6), a membrane protein (SGCD), a channel protein (KCNMA1), and a protein kinase (PRKG1). The knock-down of KCNMA1 by siRNA showed increased sensitivity to selenium in both LNCaP and PC3 cell lines. Furthermore, SNP-SNP interaction (epistasis) analysis indicated the interactions of the SNPs in AKAP6 with SGCD as well as SNPs in AKAP6 with KCNMA1 with each other, assuming additive genetic model. These genes were also all involved in the Ca2+ signaling, which has a direct role in induction of apoptosis and induction of apoptosis in tumor cells is consistent with the chemopreventive action of selenium. Once our findings are further validated, this knowledge can be translated into clinics where individuals who can benefit from the chemopreventive characteristics of the selenium supplementation will be easily identified using a simple DNA analysis. 相似文献
40.
Franke Volbeda Nick HT ten Hacken Monique E Lodewijk Antoon Dijkstra Machteld N Hylkema M Broekema Wim Timens Dirkje S Postma 《Respiratory research》2010,11(1):106