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排序方式: 共有620条查询结果,搜索用时 15 毫秒
611.
Stable cavitation induces increased cytoplasmic calcium in L929 fibroblasts exposed to 1-MHz pulsed ultrasound 总被引:2,自引:0,他引:2
An increase in cytoplasmic calcium (Ca2+ increase) is a second messenger that is often observed under ultrasound irradiation. We hypothesize that cavitation is a physical mechanism that underlies the increase in Ca2+ in these experiments. To control the presence of cavitation, the wave type was controlled in a sonication chamber. One wave type largely contained a traveling wave (wave type A) while the other wave type largely contained a standing wave (wave type B). Fast Fourier transform (FFT) analysis of a sound field produced by the wave types ascertained that stable cavitation was present only under wave type A ultrasound irradiation. Under the two controlled wave types, the increase in Ca2+ in L929 fibroblasts was observed with fluorescence imaging. Under wave type A ultrasound irradiation, an increase in Ca2+ was observed; however, no increase in Ca2+ was observed under wave type B ultrasound irradiation. We conclude that stable cavitation is involved in the increase of Ca2+ in cells subjected to pulsed ultrasound. 相似文献
612.
Agata Roguska Sachiko Hiromoto Akiko YamamotoMicha? Jerzy Wo?niak Marcin Pisarek Ma?gorzata Lewandowska 《Applied Surface Science》2011,257(11):5037-5045
Collagen fibril/(calcium phosphate and carbonate) composite coatings on 316L stainless steel were developed with a cathodic deposition technique. The response of SaOS-2 osteoblast-like cells to the collagen/calcium salt-coated 316L steel was investigated. The collagen fibrils were self-assembled on the 316L steel surface and immobilized by their partial incorporation into a calcium salt layer electrodeposited cathodically in Hanks’ solution. The amount of calcium salt depended on the applied cathodic potential. The mineralization of collagen fibrils was observed. The collagen coverage localized and the composition of calcium salts varied on the same specimen. Such non-uniform surfaces affected the cell response. The observed outlines of cell bodies and nuclei on the thin collagen coating were clearer than those on the thick collagen coating in most cases. The collagen coating did not significantly influence the mean viability of cells on the whole specimen surface. Interestingly, the alkaline phosphatase activity per cell on the collagen/calcium salt-coated specimens was higher than that on the as-received specimen. It was revealed that cathodic deposition is an effective technique to immobilize collagen fibrils on a 316L steel surface. 相似文献
613.
Finefield JM Greshock TJ Sherman DH Tsukamoto S Williams RM 《Tetrahedron letters》2011,52(16):1987-1989
Notoamide E, a short-lived secondary metabolite, has been proposed as a biosynthetic intermediate to several advanced metabolites isolated from Aspergillus versicolor. In order to verify the role of this indole alkaloid along the biosynthetic pathway, synthetic doubly 13C-labeled notoamide E was fed to Aspergillus versicolor. Analysis of the metabolites showed significant incorporation of notoamide E into the natural products notoamides C and D. 相似文献
614.
Yumiko NagasawaHikaru Kato Henki Rotinsulu Remy E.P. MangindaanNicole J. de Voogd Sachiko Tsukamoto 《Tetrahedron letters》2011,52(41):5342-5344
Spironaamidine (1), a unique spiroquinone-containing alkaloid, was isolated from the marine sponge, Leucetta microraphis, along with two known imidazole alkaloids, naamidine H (2) and (9E)-clathridine 9-N-(2-sulfoethyl)imine (3). Spironaamidine (1) showed antimicrobial activity against Bacillus cereus. 相似文献
615.
Yumiko MatsutaTakayuki Kobari Sachiko KurashimaYuhsuke Kumakura Masashi ShinadaKazuhiro Higuchi Tomomi Kawasaki 《Tetrahedron letters》2011,52(46):6199-6202
An efficient approach to spirocyclic oxindole architecture with vicinal quaternary carbon centers is described. The reaction of 2-allyloxyindolin-3-ones with cyanomethylphosphonate at low reaction temperature proceeds smoothly with consecutive olefination, isomerization, deacylation, and anion-accelerated Claisen rearrangement to give the 3,3-disubstituted oxindoles with vicinal quaternary all-carbon centers in high yield and diastereoselectivity. The oxindoles are readily converted into more synthetically advanced spiro-products. 相似文献
616.
617.
Y. Kanai M. Saiki K. Hirasawa T. Tsukamoto K. Yoshida S.J. Greaves H. Muraoka 《Journal of magnetism and magnetic materials》2008,320(14):e287-e290
A Landau–Lifshitz–Gilbert (LLG) micromagnetic analysis of the recording field of single-pole-type (SPT) heads was carried out. The whole volume comprising the SPT head and the double-layered medium was treated micromagnetically using the finite-difference method with cubic cells as small as 5 nm, giving a total number of cells of more than 10.8 million. A parallelized fast Fourier transform (FFT) method was used to solve this large-scale problem. Dynamic recording fields were calculated for various head structures and head materials. The timing (synchronization) between the dynamic head field and land location in bit-patterned media (BPM) is discussed and the design methodology is discussed for a fast-switching SPT head. 相似文献
618.
Y. Kanai K. Hirasawa T. Tsukamoto K. Yoshida S. Greaves H. Muraoka 《Journal of magnetism and magnetic materials》2008
Single-pole-type (SPT) heads for perpendicular magnetic recording were investigated using a Landau–Lifshitz–Gilbert (LLG) micromagnetic analysis program running on a PC cluster system. Dynamic recording fields were calculated for various driving currents, head structures and head materials. The dynamic head field response is discussed with regard to the write timing window for bit-patterned media, as described in previous papers. 相似文献
619.
Hisanori Muramatsu Tetsuya Kambe Takamasa Tsukamoto Takane Imaoka Kimihisa Yamamoto 《Molecules (Basel, Switzerland)》2022,27(11)
Superatoms are promising materials for their potential in elemental substitution and as new building blocks. Thus far, various synthesis methods of thiol-protected Au clusters including an Au25 superatom have been investigated. However, previously reported methods were mainly depending on the thermodynamic stability of the aimed clusters. In this report, a synthesis method for thiol-protected Au clusters using a dendrimers template is proposed. In this method, the number of Au atoms was controlled by the stepwise complexation feature of a phenylazomethine dendrimer. Therefore, synthesis speed was increased compared with the case without the dendrimer template. Hybridization for the Au25 superatoms was also achieved using the complexation control of metals. 相似文献
620.
Kazunobu Sugihara Sachiko Kaidzu Masahiro Sasaki Sho Ichioka Yuji Takayanagi Hiroshi Shimizu Ichiya Sano Katsunori Hara Masaki Tanito 《Photochemistry and photobiology》2023,99(3):967-974
Two krypton-chloride germicidal excimer lamp units (Care222 TRT-104C11-UI-U3, USHIO Inc.) were installed in the examination room of an ophthalmology department. The irradiation dose was set not to exceed the former (i.e., before 2022) threshold limit value (TLV) (22 mJ cm−2/8 h) recommended by the ACGIH. Section 1: The eyes and lids of the six ophthalmologists (5 wore glasses for myopic correction) who worked in the room for a mean stay of 6.7 h week−1 were prospectively observed for 12 months. Slitlamp examinations revealed neither acute adverse events such as corneal erosion, conjunctival hyperemia, and lid skin erythema nor chronic adverse events such as pterygium, cataract, or lid tumor. The visual acuity, refractive error, and corneal endothelial cell density remained unchanged during the study. Section 2: The irradiation of samples placed on the table or floor using the same fixtures in the room (5–7.5 mJ cm−2) was associated with >99% inhibition of φX174 phage and >90% inhibition of Staphylococcus aureus. In conclusion, no acute or chronic health effects in human participants was observed in a clinical setting of full-room ultraviolet germicidal irradiation by 222-nm lamp units, and high efficacy in deactivation of microorganisms was determined in the same setting. 相似文献