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81.
Guanbin Song Yang Ju Hitoshi Soyama 《Materials science & engineering. C, Materials for biological applications》2008,28(8):1467-1471
Bone marrow mesenchymal stem cells (MSCs) can differentiate into a various type cells. It has been identified that MSCs are an attractive cell source for various tissue engineering and play a central role in the repair and regeneration of mesenchymal tissue. Expansion of MSCs in vitro is prerequisite for their applications in tissue engineering. In this study, we evaluated the effects of type I collagen (Col I), fibronectin (Fn) and basic fibroblast growth factor (bFGF) on growth and proliferation of human MSCs (hMSCs) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetra-zolium bromide (MTT) assay. Our results show that low-dose bFGF (5–20 ng/ml) has a promotion effects for growth and proliferation of hMSCs. The proliferation, however, was back to the level similar to the control one (without bFGF treatment) after exposure to high-dose bFGF (40 ng/ml). Application of Col I, coating on the silicone surface or mixed with medium directly, yielded an obvious decrease in growth and proliferation of hMSCs. Moreover, the inhibitory effects exhibited a dose-dependence manner. On the other hand, Fn coating did not promote the growth and proliferation of hMSCs, and also did not inhibit proliferation, but enhanced the adhesion of hMSCs to silicone surface. These findings indicate that Col I decreases the growth and proliferation of hMSCs and is not suitable for encouraging expansion of hMSCs in vitro. Low-dose bFGF could be preferred as medium supplementation for hMSCs expansion and Fn is a better coating material for hMSCs adhesion. 相似文献
82.
This paper describes an efficient contention resolution algorithm and its distributed implementation for large capacity input queuing cross-connect switches, which will establish virtual paths in future broadband ATM networks. The algorithm dynamically allocates sending time to cells held in input queues when no contention is indicated in the designated output ports. An expression for the mean delay and the cell loss probability for random traffic are derived through an approximate analysis. Input cells are served on a first-come, first-served basis as conventional contention resolution algorithms whose throughput saturates at 58 per cent because of head of line blocking in input queues. The proposed algorithm achieves a maximum throughput of 76 per cent. 相似文献
83.
Isao Kagomiya Shinji Matsumoto Ken-ichi Kakimoto Hitoshi Ohsato Hiroshi Sakai Yukinori Maeda 《Journal of the European Ceramic Society》2013,33(5):985-990
We investigated annealing effects of La1?xSrxMnO3 (x = 0–0.6) on electrical resistivity and the temperature coefficient of resistivity (TCR). The annealed samples’ resistivity was lower than those of non-annealed samples. For example, annealing changed the resistivity of x = 0.3 at 25 °C from 4.50 × 10?5 to 3.71 × 10?5 Ω m. Remarkable difference in TCR was observed after annealing, for x = 0.3, 0.45, and 0.5. For x = 0.3, the TCR after annealing was 4000 ppm/°C, which was 1250 ppm/°C greater than that before annealing. We investigated (1) crystal phase, (2) Mn average valence, (3) Mott insulator–metal transition temperature, and (4) microstructure. The microstructure was remarkably varied for annealed x = 0.3 and 0.5. The average grain size of the x = 0.3 increased from 1.60 up to 2.38 μm. Results show that annealing affects resistivity and TCR because of grain growth during annealing. 相似文献
84.
85.
Development of multianode photomultiplier tube 总被引:1,自引:0,他引:1
Fumuhiko Takasaki Hitoshi Saito Tohru Fukui Teruhiko Matsushita Toshihiro Suzuki 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1987,260(2-3):447-450
We have developed a multianode photomultiplier tube (MAPMT) which has a sensitive cathode diameter of 36 mm and an anode with 88 segments. The position sensitivity of the tube was studied by using light from a LED and scintillation light from a scintillation-fiber bundle. We observed particle tracks for the first time by using a single photomultiplier tube. 相似文献
86.
Toshiki Yamada Hidenori Shinohara Toshiya Kamikado Yoshishige Okuno Hitoshi Suzuki Shinro Mashiko Shiyoshi Yokoyama 《Thin solid films》2008,516(9):2522-2526
The spray-jet molecular beam apparatus enabled us to produce a molecular beam of non-volatile molecules under high vacuum from a sprayed mist of sample solutions. The apparatus has been used in spectroscopic studies and as a means of molecular beam deposition. We analyzed the molecular beam, consisting of non-volatile, solvent, and carrier-gas molecules, by using femtosecond- and nanosecond- laser mass spectroscopy. The information thus obtained provided insight into the molecular beam produced by the spray-jet technique. 相似文献
87.
Accelerated Genetic Programming of Polynomials 总被引:1,自引:0,他引:1
An accelerated polynomial construction technique for genetic programming is proposed. This is a horizontal technique for gradual expansion of a partial polynomial during traversal of its tree-structured representation. The coefficients of the partial polynomial and the coefficient of the new term are calculated by a rapid recurrent least squares (RLS) fitting method. When used for genetic programming (GP) of polynomials this technique enables us not only to achieve fast estimation of the coefficients, but also leads to power series models that differ from those of traditional Koza-style GP and from those of the previous GP with polynomials STROGANOFF. We demonstrate that the accelerated GP is sucessful in that it evolves solutions with greater generalization capacity than STROGANOFF and traditional GP on symbolic regression, pattern recognition, and financial time-series prediction tasks. 相似文献
88.
Tomoyuki Kawase Kazuhiro Okuda Hiroyuki Kogami Hitoshi Nakayama Masaki Nagata Hiromasa Yoshie 《Journal of materials science. Materials in medicine》2010,21(2):731-739
Our animal implantation studies have demonstrated that, after osteogenic processing, cultured human periosteal sheets form
osteoid tissue ectopically without the aid of conventional scaffolding materials. To improve the osteogenic activity of these
periosteal sheets, we have tested the effects of including a scaffold made of salmon collagen-coated ePTFE mesh. Periosteal
sheets were produced with minimal manipulation without enzymatic digestion. Outgrown cells penetrated into the coated mesh
fiber networks to form complex multicellular layers and increased expression of alkaline phosphatase activity in response
to the osteoinduction. In vitro mineralization was notably enhanced in the original tissue segment regions, but numerous micro-mineral
deposits were also formed on the coated-fiber networks. When implanted subcutaneously into nude mice, periosteal sheets efficiently
form osteoid around the mineral deposits. These findings suggest that the intricate three-dimensional mesh composed of collagen-coated
fibers substantially augmented the osteogenic activity of human periosteal sheets both in vitro and in vivo. 相似文献
89.
Kento Nishida Hiroshi Watanabe Ryota Murata Kai Tokumaru Rui Fujimura Shun Oshiro Taisei Nagasaki Masako Miyahisa Yuto Hiramoto Hiroto Nosaki Tadashi Imafuku Hitoshi Maeda Masafumi Fukagawa Toru Maruyama 《International journal of molecular sciences》2021,22(11)
An effective strategy is highly desirable for preventing acute kidney injury (AKI) to chronic kidney disease (CKD) transition. Thioredoxin-1 (Trx), a redox-active protein that has anti-oxidative and anti-inflammatory properties, would be a candidate for this but its short half-life limits its clinical application. In this study, we examined the renoprotective effect of long-acting Trx that is comprised of human albumin and Trx (HSA-Trx) against AKI to CKD transition. AKI to CKD mice were created by renal ischemia-reperfusion (IR). From day 1 to day 14 after renal IR, the recovery of renal function was accelerated by HSA-Trx administration. On day 14, HSA-Trx reduced renal fibrosis compared with PBS treatment. At the early phase of fibrogenesis (day 7), HSA-Trx treatment suppressed renal oxidative stress, pro-inflammatory cytokine production and macrophage infiltration, thus ameliorating tubular injury and fibrosis. In addition, HSA-Trx treatment inhibited G2/M cell cycle arrest and apoptosis in renal tubular cells. While renal Trx protein levels were decreased after renal IR, the levels were recovered by HSA-Trx treatment. Together, HSA-Trx has potential for use in the treatment of AKI to CKD transition via its effects of modulating oxidative stress and inflammation. 相似文献