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排序方式: 共有1465条查询结果,搜索用时 15 毫秒
1.
Halil Erhan Eroğlu Ahmet Aksoy Ergin Hamzaoğlu Ümit Budak Sevil Albayrak 《Cytotechnology》2009,59(1):65-72
Helichrysum Mill. (Asteraceae) species have been used in folk medicine for thousands of years in the world. The in vitro cytogenetic
effects in human lymphocytes of nine Helichrysum taxa used in Turkey folk medicine were investigated. Blood samples were obtained from healthy donors, non-smoking volunteers,
which were incubated and exposed to increasing concentrations of methanol extracts of Helichrysum taxa (0.01, 0.05, 0.1, 0.5 and 1 mg/mL). The inhibitory effects of H. stoechas (L.) Moench subsp. barrelieri (Ten.) Nyman, H. armenium DC. subsp. armenium, H. armenium DC. subsp. araxinum (Kirp.) Takht., H. plicatum DC. subsp. plicatum, H. compactum Boiss. and H. artvinense P.H.Davis & Kupicha on the mitotic index and replication index indicate that these taxa can have genotoxic and mutagenic
effects. They should therefore not be used freely in alternative medicine although their antiproliferative activity may suggest
anticarcinogenic properties. Increase effects of H. stoechas subsp. barrelieri, H. armenium subsp. armenium, H. armenium subsp. araxinum, H. chasmolycicum P.H.Davis, H. plicatum subsp. plicatum, H. compactum and H. artvinense on the micronucleus rates showed that these taxa can have genotoxic and carcinogenic effects. 相似文献
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Heteroduplex formation is known to occur during mixed-template polymerase chain reaction (PCR) using universal primers, and
may represent a serious problem in several PCR-based analyses. A common way to eliminate heteroduplex formation is to use
reconditioning PCR. Because we detected that reconditioning PCR was not always sufficient to prevent heteroduplex formation,
we focused on developing methods for the elimination of heteroduplexes during PCR. We detected that the heteroduplex to homoduplex
ratio can be decreased by the addition of Taq polymerase and by a decrease in the number of PCR cycles. An appropriate combination of both of these approaches can be a
method generally applicable to decrease the formation of heteroduplexes. 相似文献
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C D Olinici E R?dulescu I C?lu?er M Giurgiuman I Macavei E Marinca 《Morphologie et embryologie》1980,26(4):341-344
The incidence of micronuclei in bone marrow erythroblasts of patients with pernicious anemia ranged between 0.5-5.6% as compared with the value of 0-0.5% noted in hematologically healthy patients. The mechanism of formation and the possible significance of micronuclei in megaloblastic anemia are briefly discussed. 相似文献
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Journal of Plant Growth Regulation - Herbicides inhibit plant growth and development by various mechanisms, and oxidative stress is a common plant response to herbicide treatment. In a limited... 相似文献
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Canan Bural Gülsen Bayraktar Ismail Aydin İbrahim Yusufoğlu Natuk Uyumaz Mete Hanzade 《Gerodontology》2010,27(3):217-223
doi:10.1111/j.1741‐2358.2009.00321.x Flexural properties of repaired heat‐polymerising acrylic resin after wetting with monomer and acetone Objectives: Repair strength can be improved by treating fractured surfaces of a denture. Background: This study investigated flexural properties of heat‐polymerised acrylic resin specimens repaired with auto‐polymerising and visible light curing (VLC) resins after the repair surfaces were wetted with monomers or acetone. Materials and Methods: Fifty‐four specimens (65 × 10 × 2.5 mm) were prepared and 48 of them were sectioned to simulate denture fracture. Butt‐joint designed repair surfaces were wetted with heat‐, auto‐polymerising monomers and acetone for 180 s and repaired with auto‐polymerising and VLC resins. After repairs, specimens were subjected to three‐point bending test and flexural strength, strain, fracture load, modulus of elasticity and deflection values were recorded. Data were analysed with Student t and LSD tests (p ≤ 0.05). Results: Overall flexural strength, strain, fracture load and deflection values of specimens repaired with VLC resin were significantly higher than the specimens repaired with auto‐polymerising resin for all types of wetting agent (p < 0.05). Within the wetting agents, heat‐ and auto‐polymerising monomers produced the best mechanical properties, while wetting with acetone did not provide superior effect over both monomers. Conclusion: In clinical use, wetting the repair surfaces may result in stronger repairs. The use of bonding agent in VLC resin repairs in combination with wetting agent results in improved flexural properties. 相似文献
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Exposure of hamster pancreatic islets to hyaluronidase during isolation by means of collagenase inhibits the insulinotropic action of several chemically different sulfonylureas, leucine, and glucagon without affecting glucose-stimulated insulin secretion. This inhibition is reversible for tolbutamide and leucine but irreversible for glucagon. Hyaluronidase inhibits reversibly the insulinotropic action of tolbutamide without affecting that of glucose also in mouse and rat isolated pancreatic islets . These findings suggest the existence of functionally related pancreatic beta cell receptors for tolbutamide and leucine different from those for glucose and glucagon and illustrate the potential usefulness of hyaluronidase as an enzymatic probe applicable toward investigating the cellular mechanism of action of key insulinotropic agents. 相似文献
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