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301.
Shibuya M 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2011,87(4):167-178
We previously isolated a novel tyrosine kinase receptor, Flt-1, now known as VEGF-receptor (VEGFR)-1. The VEGF-VEGFR system plays a pivotal role in not only physiological but also pathological angiogenesis. We examined the role of Flt-1 in carcinogenesis using Flt-1-signal-deficient (Flt-1 TK-/-) mice, and found that this receptor stimulates tumor growth and metastasis most likely via macrophages, making it an important potential target in the treatment of cancer. In addition to the full-length receptor, the Flt-1 gene produces a soluble protein, sFlt-1, an endogenous VEGF-inhibitor. sFlt-1 is expressed in trophoblasts of the placenta between fetal and maternal blood vessels, suggesting it to be a barrier against extreme VEGF-signaling. Abnormally high expression of sFlt-1 occurs in most preeclampsia patients, whose main symptoms are hypertension and proteinurea. In cancer patients, strong suppression of VEGF-VEGFR by drugs induces similar side effects including hypertension. These results indicate a close relationship between abnormal VEGF-block and hypertension/proteinurea. sFlt-1 is an attractive target for the control of preeclampsia. 相似文献
302.
A new one-pot method for the synthesis of alpha-siloxyamides is described. The three substrates, H-C(CN)(2)O-SiMe(2)t-Bu, aldehydes or ketones, and primary or secondary amines, are simply mixed in one portion in acetonitrile or ether; the alpha-siloxyamides are obtained within short peroids in excellent yields in many cases. As a demonstration of our method, the synthesis of (-)-bestatin was carried out. 相似文献
303.
Ryotaro Sekine Takashi Shibuya Kazuhiko Ukai Shinichi Komatsu Masayuki Hattori Toshifumi Mihashi Naoki Nakazawa Yoko Hirohara 《Optical Review》2006,13(4):207-211
The measurement of human ocular aberration is now frequently performed because of the increase in refractive surgery on the
human cornea. The Hartmann-Shack (H-S) wavefront sensor is considered to be the most useful wavefront sensor, and a calculation
method for wavefront aberration has been established. New methods of measuring wavefront aberrations of human eyes, using
the Talbot image of a two-dimensional grating as a wavefront sensor and local shift of the Talbot image to calculate tilt
of the wavefront are shown. The shift of the Talbot image was determined by comparing the phases of fundamental spatial frequency
between the grating and the local patch of the Talbot image by Fourier transformation. The actual experiment was performed
using a modified commercially available wavefront analyzer. Using these methods, Talbot images were obtained from model eyes
and a human eye, and wavefront shapes were successfully reconstructed. Wavefront aberrations can be measured even when the
obtained image is degraded by defocusing or scattering. 相似文献
304.
Satoshi Hamatani Kazuhide Tsuji Akio Kawai Kazuhiko Shibuya 《Chemical physics letters》2002,360(5-6):466-472
We measured the laser-induced fluorescence (LIF) and dispersed fluorescence (DF) spectra of jet-cooled -, o- and m-chlorobenzyl radicals after they were generated by the 193 nm photolysis of the corresponding parent molecules. The vibronically resolved spectra were obtained to analyze their D1–D0 transitions. The fluorescence lifetimes of -, o-, m- and p-chlorobenzyls in the zeroth vibrational levels of the D1 states were measured to estimate the oscillator strengths of a series of benzyl derivatives. It was found that the -substitution is inefficient to break the ‘accidental forbiddenness' of the D1–D0 transition of benzyl, while the ring-substitution enhances the oscillator strength by 50%. 相似文献
305.
Juzo Nakayama Ayako Kaneko Yoshiaki Sugihara Akihiko Ishii Akihiro Oishi Isao Shibuya 《Heteroatom Chemistry》2000,11(6):434-440
It was shown that dimethyl 2‐thiono‐1,3‐dithiole‐4,5‐dicarboxylate ( 2 ) and dimethyl acetylenedicarboxylate (DMAD) undergo a 1,3‐dipolar cycloaddition to produce a short‐lived ylide intermediate ( 3 ). The 1,3‐dipolar cycloaddition took place even at room temperature, although sluggishly, but took place much more rapidly under application of a high pressure of 500 MPa. The 1,3‐dipolar cycloaddition is reversible and the ylide 3 immediately splits into 2 and DMAD. When the reaction of 2 with DMAD was carried out at room temperature without solvent, a spiro‐1,3‐dithiole ( 11 ) was formed in 11% yield, whereas the reaction at 150°C provided a thiophene derivative ( 13 ) in 41% yield. It was found that 11 undergoes a thermal rearrangement to 13 . Results of attempted chemical trapping of the ylide 3 are also reported. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:434–440, 2000 相似文献