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1.
Endoscopic Observation of Tissue by Narrowband Illumination 总被引:6,自引:0,他引:6
Kazuhiro Gono Kenji Yamazaki Nobuyuki Doguchi Tetsuo Nonami Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama Hirohisa Machida Yasushi Sano Shigeaki Yoshida Yasuo Hamamoto Takao Endo 《Optical Review》2003,10(4):211-215
We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer. 相似文献
2.
35Cl NQR as well as heat capacity measurements of [(PyO)H][AuCl4] and its deuterated analog [(PyO)D][AuCl4] revealed successive phase transitions at 70.5 and 62.5 K, and at 71 and 63 K, respectively. The NQR frequency varied continuously through the upper transition point while discontinuously through the lower transition point. In the intermediate-temperature phase a remarkable decrease in the signal intensity was observed. These NQR observations as well as the feature of the heat capacity anomaly in which a broad peak is succeeded by a sharp peak with decreasing temperature suggest a possibility of normal-incommensurate-commensurate phase sequence. 相似文献
3.
In proportion to the environmental pollution problems caused by organotin compounds, the genotoxicities of tin compounds in the environments have become of interest so as to estimate their safety in recent years. In this work, isolated λ-DNA (double-strand DNA) was incubated with inorganic tin(II) and tin(IV) and five organotin compounds [n-butyltin trichloride, di(n-butyltin) dichloride, methyltin trichloride, dimethyltin dichloride and trimethyltin chloride] in reaction systems both with and without hydrogen peroxide (H2O2) content. The tin compounds tested in this study did not induce DNA breakage in the absence of hydrogen peroxide. Divalent inorganic tin (SnCl2) and tetravalent inorganic tin (SnCl4) caused DNA breakage in the presence of hydrogen peroxide (10 mM), and the DNA damage activity of inorganic tin was much more potent in divalent inorganic tin (SnCl2) than in tetravalent inorganic tin (SnCl4). Divalent inorganic tin (SnCl2) induced DNA breakage in a concentration-dependent fashion at concentrations greater than 0.1 mM of SnCl2 in the presence of hydrogen peroxide (10 mM). DNA breakage was not caused by n-butyltin compounds and methyltin compounds either in the presence or in the absence of hydrogen peroxide. 相似文献
4.
5.
Let m be an integer with m3. Let K and K be perfect fields of characteristic p and p such that (p,m)=1 and (p,m)=1, respectively. Moreover let A and A be algebraic function fields over K and K defined by xm+ym=a(0, ak) and xm+ym=a(a0 ak), respectively. Put g=(m–1)(m–2)/2. Denote by M(K,p,a) and M(K,p,a) the Hasse-Witt matrices of A and A with respect to the canonical bases of holomorphic differentials. Then we show that if p+p0(mod.m) then rank M(K,p,a)+rank M(K,p,a)=g and if pp1 (mod.m) then rank M(K,p,a)=rank M(K,p,a). 相似文献
6.
7.
The super-macromolecular complex, succinate:quinone oxidoreductase (SQR, Complex II, succinate dehydrogenase) couples the oxidation of succinate in the matrix / cytoplasm to the reduction of quinone in the membrane. This function directly connects the Krebs cycle and the aerobic respiratory chain. Until the recent first report of the structure of SQR from Escherichia coli (E. coli) the structure-function relationships in SQR have been inferred from the structures of the homologous QFR, which catalyses the same reaction in the opposite direction. The structure of SQR from E. coli, analogous to the mitochondrial respiratory Complex II, has provided new insight into SQR's molecular design and mechanism, revealing the electron transport pathway through the enzyme. Comparison of the structures of SQR, QFR and other related flavoproteins shows how common amino acid residues at the interface of two domains facilitate the inter-conversion of succinate and fumarate. Additionally, the structure has provided a possible explanation as to why certain organisms utilise both SQR and QFR despite the fact that both can catalyse the inter-conversion of succinate and fumarate, in vitro and in vivo. Here we review how this structure has advanced our knowledge of this important enzyme and compare the structural information to other members of the Complex II superfamily and related flavoproteins. 相似文献
8.
Complexation of a hydrophobic thiazorylazophenol with Ni2+ at sodium dodecylsulfate micellar surface
Complexation of thiazorylazododecylphenol (TADP) with Ni2+ at the surface of sodium dodecylsulfate (SDS) micelles has been spectrophotometrically studied. Complicated spectral changes are analyzed by a factor and multivariate analysis, which implies the formation of [TDAP(OH-)Ni]0 as well as a simple 1:1 complex of Ni2+ with TDAP at the micellar interface. All of the equilibrium constants required to describe this system are substantially affected by electrolyte concentrations. Coexistent electrolytes vary the surface potential of the micelle, and in turn influence the equilibria taking place on the micellar surface. The electrostatic potential estimated based on the equilibrium shifts is more negative than that calculated according to Poisson-Boltzmann theory, which simply involves electrostatic effects. This disagreement is possibly caused by different aqueous environments around the micelle from bulk solution, which also facilitate the formation of unusual complex such as [TDAP(OH-)Ni]0. 相似文献
9.
de Kort M Regenbogen AD Valentijn AR Challiss RA Iwata Y Miyamoto S van der Marel GA van Boom JH 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(15):2696-2704
The synthesis, biological evaluation, and molecular modeling of two conformationally restricted analogues of adenophostinA (1), denominated as spirophostin (3R)-10 and (3S)-11, as novel ligands for the D-myo-inositol 1,4,5-trisphosphate receptor (IP3R), is presented. These diastereoisomeric spiroketals are synthesized by spiroketalization of D-glucose derivatives (2S)-15 and (2R)-16, separation of the protected isomers (3R)-19 and (3S)-20, followed by phosphorylation and deprotection. The spirophostins (3R)-10 and (3S)-11 display comparable biological activity, with a 3H-IP3-displacing and Ca2+-releasing potency less than IP3 and adenophostin A. 相似文献
10.