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排序方式: 共有1482条查询结果,搜索用时 31 毫秒
91.
A mammalian genetic system to screen for small molecules capable of disrupting protein-protein interactions 总被引:2,自引:0,他引:2
Zhao HF Kiyota T Chowdhury S Purisima E Banville D Konishi Y Shen SH 《Analytical chemistry》2004,76(10):2922-2927
A mammalian two-hybrid system was developed for high-throughput screening of compounds that disrupt specific protein-protein interactions. The existing mammalian systems are unsatisfactory for drug screening due to nonregulated expression of interacting proteins. To construct a tightly regulated system, the tetracycline repressor was fused with the inhibitory KRAB domain as a suppressor. The binding of the suppressor to the tet operator entirely blocked expression of two interacting proteins. When both the inducer doxycycline and drugs were added to the culture, the reporter gene was either activated by interaction of the paired proteins with ineffective drugs or remained silent due to disruption of the protein interactions by the effective drugs. We demonstrate that interactions of the type I receptor for TGFbeta with FKBP12 and the epidermal growth factor receptor (EGFR) with p85 are effectively disrupted by FK506 and EGFR kinase inhibitor AG1478, respectively. The power of this system for drug screening was further demonstrated by rapid identification of inhibitors from a druglike library for the receptor kinases. 相似文献
92.
Kitamura Y Shogenji R Yamada K Miyatake S Miyamoto M Morimoto T Masaki Y Kondou N Miyazaki D Tanida J Ichioka Y 《Applied optics》2004,43(8):1719-1727
The authors have proposed an architecture for a compact image-capturing system called TOMBO (thin observation module by bound optics), which uses compound-eye imaging for a compact hardware configuration [Appl. Opt. 40, 1806 (2001)]. The captured compound image is decomposed into a set of unit images, then the pixels in the unit images are processed with digital processing to retrieve the target image. A new method for high-resolution image reconstruction, called a pixel rearrange method, is proposed. The relation between the target object and the captured signals is estimated and utilized to rearrange the original pixel information. Experimental results show the effectiveness of the proposed method. In the experimental TOMBO system, the resolution obtained is four times higher than that of the unit image that did not undergo reconstruction processing. 相似文献
93.
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95.
Internal oxidation was observed in gold-rich alloys as substrates for porcelain veneers in dental restorations, which contain small amounts of Fe and Sn. The internal oxidation proceeded with oxygen ions diffusing to the inner part of the alloy through Fe2O3 formed at the grain boundaries of the alloy matrix. SnO2 was formed internally together with the Fe2O3. The external oxidation zone was composed of only Fe2O3 in a wide range of Fe and Sn concentrations. Fe3O4 was formed with Fe2O3 in the Sn-rich composition range by reduction of Fe2O3 in the presence of Sn. A band mainly composed of SnO2 was formed at the inside of the internal oxidation zone in the composition range where Fe3O4 formed. In the Sn-rich alloys this internal oxidation band of SnO2 moved to the external oxidation zone. 相似文献
96.
Yasuo Harayama 《Nuclear Engineering and Design》1974,31(1):66-71
The effect of radially asymmetric heat generation on the temperature and heat flux distribution in a fuel rod is evaluated. Based on practical assumptions, the temperature distribution in power reactor fuel can be obtained between reasonable limits by solving the steady-state heat conduction equation with asymmetric heat generation. 相似文献
97.
Remineralization effects of xylitol on demineralized enamel 总被引:3,自引:0,他引:3
We morphologically determined the effects of xylitol on the remineralization of artificially demineralized enamel. The samples were demineralized and then immersed in a remineralizing solution with or without 20% xylitol at 37 degrees C for 2 weeks. Samples were observed using contact microradiography, a multipurpose image processor (MIP) and a high-resolution electron microscope (HRTEM). Contact microradiography indicated that remineralization occurred in the surface and deep layers of samples immersed in a non-xylitol solution. Samples immersed in a xylitol solution demonstrated less mineralization in the outer 10 microm of the outermost surface layers, but more mineralization in the middle and deep layers, than was observed in the non-xylitol samples. The MIP evaluation indicated that remineralization was more prominent in layers at depths of 50-60 microm in the xylitol samples than in the non-xylitol samples. Observation of the xylitol samples by HRTEM revealed crystals of various sizes and irregular shapes with unclear crystal angles in the outermost surface layers. In the middle layers, they had thickened and angles of crystals are clear. These results indicate that xylitol can induce remineralization of deeper layers of demineralized enamel by facilitating Ca2+ movement and accessibility. 相似文献
98.
Porous membrane tubes filled with an absorbing solution that change colors upon selective reactions with specific gases provide high sensitivity inexpensive gas sensors. These can be routinely used for ambient monitoring in a fully automated manner. We consider both stopped and continuous flow operations and show the superiority of the stopped flow mode theoretically and experimentally. Light throughput through various membrane tubes is presented, and superior performance of such tubes over Teflon AF is shown. Sensors for NO2 and for O3 were based on Griess-Saltzman and indigotrisulfonate chemistries, respectively. A computer-controlled two-LED absorbance measurement system (one wavelength monitors the signal, the other references the system) that also governs automated reagent refilling was implemented. Sub-parts-per-billion-volume detection limits are attainable within a few minutes for both gases. Comparative data with a commercial UV-photometry-based ozone monitor showed excellent agreement with the response pattern of the present instrument. Low cost, ready applicability to the measurement of different gases by merely changing the light source and chemistry, and high sensitivity makes this instrument attractive for both pedagogic and practical purposes. 相似文献
99.
Chunqing?HeEmail author Takenori?Suzuki Eisaku?Hamada Hitoshi?Kobayashi Kenjiro?Kondo Victor?P.?Shantarovich Yasuo?Ito 《Materials Research Innovations》2003,7(1):37-41
Polymer structures have been investigated using positron annihilation lifetime spectroscopy (PALS) with a slow positron beam
as well as a conventional radioactive source (22Na). The properties of the free volume holes near the polymer surface were studied as a function of the positron implantation
energy. The longest lifetime was associated with ortho-positronium (o-Ps) annihilation in the free volume holes. In polytetrafluoroethylene film, the lifetime of o-Ps was observed to decrease with increasing positron implantation depth, and a significant change in the o-Ps lifetime was found at a short distance (about 10 nm) from the surface, while its intensity increased. This result implies
that near the polymer surface the free volume holes become larger that in the bulk. The effect of temperature on the polymer
sub-surface layers was also studied. For high molecular weight polystyrene, the glass transition temperature for the sub-surface
was lower than that for the bulk and thermal expansion coefficient of the sub-surface layers was found to be larger than the
bulk value.
Electronic Publication 相似文献
100.
Ambulatory biosensor assessment includes a diverse set of rapidly developing and increasingly technologically sophisticated strategies to acquire minimally disruptive measures of physiological and motor variables of persons in their natural environments. Numerous studies have measured cardiovascular variables, physical activity, and biochemicals such as cortisol in psychopathology and treatment research. The physiological concomitants of many behavior and medical disorders and the benefits of a multimethod assessment strategy provide strong rationales for clinical applications of ambulatory biosensor measurement. A number of psychometric dimensions of evaluation are important in clinical applications of biosensor measurement, including accuracy and validity, reliability and consistency, clinical utility, incremental validity and utility, sensitivity to change, generalizability, cost benefits, and the conditional nature of dimensions of biomeasure evaluation. The authors review ambulatory biosensor methods and make recommendations for use of the technology. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献