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排序方式: 共有266条查询结果,搜索用时 78 毫秒
61.
Ultrafine Gold nanoparticles (Au NPs) functionalized with various biomolecules constitute an alternative to antibodies as anti-amyloidogenic agents. However, generating stable ultrafine Au NPs with high surface activity is challenging. Here, the capacity of phosphate groups in biomolecules is used to stabilize Au NPs. The characteristics of Au NPs decorated with adenosine mono-, di-, and tri-phosphate are compared as well as adenosine and peptide nucleic acid-containing adenosine as controls. Among them, ATP-Au NPs are found to be superior having small size (2–4 nm) and stability (for several months) when analysed by spectroscopy and electron microscopy. Spectroscopy analysis also revealed that each ATP-stabilized Au NP is decorated with 7–8 molecules of ATP. ThT binding analysis and TEM imaging showed that the ATP-Au NPs efficiently prevented amyloid fibril formation in vitro by Aβ-42, α-Synuclein as well as by the Glucosylceramide metabolite, and disaggregated their pre-formed fibrils. NMR analysis revealed the interaction of the ATP-Au NPs with the amyloid fibrils. The ATP-Au NPs are safe toward cultured SH-SY5Y cells and when co-incubated with α-Synuclein amyloids inhibited their cytotoxicity and readily enter the cells to inhibit formation of amyloid fibrils within them. The results indicates the pharmacological potentials of ATP decorated Au NPs.  相似文献   
62.
We report on a strongly coupled cavity quantum electrodynamic (CQED) system consisting of a CdSe nanocrystal coupled to a single photon mode of a polymer microsphere. The strong exciton-photon coupling is manifested by the observation of a cavity mode splitting variant Planck's over 2piOmega(exp) between 30 und 45 microeV and photon lifetime measurements of the coupled exciton-photon state. The single photon mode is isolated by lifting the mode degeneracy in a slightly deformed microsphere cavity and addressing it by high-resolution imaging spectroscopy. This cavity mode is coupled to a localized exciton of an anisotropically shaped CdSe nanocrystal that emits highly polarized light in resonance to the cavity mode and that was placed in the maximum electromagnetic field close to the microsphere surface. The exciton confined in the CdSe nanorod exhibits an optical transition dipole moment much larger than that of atoms, the standard system for CQED experiments, and a low-temperature homogeneous line width much narrower than the high-Q cavity mode width. The observation of strong coupling in a colloidal semiconductor nanocrystal-cavity system opens the way to study fundamental quantum-optics phenomena and to implement quantum information processing concepts that work in the visible spectral range and are based on solid-state nanomaterials.  相似文献   
63.
The promise of biomolecular computers is their ability to interact with naturally occurring biomolecules, enabling in the future the development of context-dependent programmable drugs. Here we show a context-sensing mechanism of a biomolecular automaton that can simultaneously sense different types of molecules, allowing future integration of biomedical knowledge on a broad range of molecular disease symptoms in the decision of a biomolecular computer to release a drug molecule.  相似文献   
64.
A number of approaches were explored for improving characteristics of the encapsulated nuclear heat source (ENHS) reactor and its fuel cycle, including: increasing the ENHS module power, power density and the specific power, making the core design insensitive to the actinides composition variation with number of fuel recycling and reducing the positive void coefficient of reactivity. Design innovations examined for power increase include intermediate heat exchanger (IHX) design optimization, riser diameter optimization, introducing a flow partition inside the riser, increasing the cooling time of the LWR discharged TRU, increasing the minor actinides' concentration in the loaded fuel and split-enrichment for power flattening. Another design innovation described utilizes a unique synergism between the use of MA and the design of reduced power ENHS cores.

Also described is a radically different ENHS reactor concept that has a solid core from which heat pipes transport the fission power to a coolant circulating around the reflector. Promising features of this design concept include enhanced decay heat removal capability; no positive void reactivity coefficient; no direct contact between the fuel clad and the coolant; a core that is more robust for transportation; higher coolant temperature potentially offering higher energy conversion efficiency and hydrogen production capability.  相似文献   

65.
The use of cutoff scores and interviews in the selection of graduate students in clinical psychology has been debated extensively, but researchers in only a few empirical studies have looked at these issues. We examined the selection process for clinical psychology students at Boston University, in which an interview was used and a quantitative cutoff score was not used. We analyzed scores of 357 applicants on Graduate Record Examinations (GRE) and Miller Analogy Tests (MAT), grade point averages (GPA), and interview ratings. We found that the major criteria for invitation to an interview were GREs and GPA, though no quantitative cutoff had been used. The use of such a cutoff would result in no difference in selection of applicants. Reliability of interview ratings was moderately high, contrary to results of previous studies. Replications of this study would add to its generalizability and argue for the use of the cutoff and further consideration of the interview. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
66.
In microscopy, regions of interest are usually much smaller than the whole slide area. Various microscopy related medical applications, such as telepathology and computer aided diagnosis, are liable to benefit greatly from microscope auto positioning on previously defined regions of interest. In this paper, we present a method for image-based auto positioning on a microscope slide. The method is based on localization of a microscopic query image using a previously acquired slide map. It uses geometric hashing, a highly efficient technique drawn from the object recognition field. The algorithm exhibits high tolerance to possible variations in visual appearance due to slide rotations, scaling and illumination changes. Experimental results indicate high reliability of the algorithm.  相似文献   
67.
Wiskott-Aldrich syndrome is an X-linked combined immunodeficiency affecting cells of several different hemopoietic lineages. The Wiskott-Aldrich syndrome protein (WASP), which has no homology with any other known protein families, is rich in proline motifs known to contribute to Src homology 3 binding sites. However, its function has not been determined. The Tec family of cytoplasmic tyrosine kinases, which include Btk (the X-linked agammaglobulinemia gene), Itk, and Tec, is thought to be involved in lymphoid cell signaling pathways. In this work, we show binding of WASP to the Src homology 3 domains of Btk, Itk, Tec, Grb2, and phospholipase C-gamma, which suggests a function for WASP in lymphoid cell signaling.  相似文献   
68.
Quantitative evaluation of product disassembly for recycling   总被引:4,自引:0,他引:4  
This paper presents a method for evaluating the ease-of-disassembly of products. Its primary use is in designing products for recycling, but it also facilitates consideration of servicing and maintenance, and making environmentally-related decisions. The method is developed and discussed in the context of relatively small products that can be disassembled by a seated person using hand-held tools. The evaluation procedure is centered around a spreadsheet-like chart and uses a catalog of task difficulty scores. The scores were derived from work-measurement analyses of standard disassembly tasks, and provide a means of identifying weaknesses in the design and comparing alternatives quantitatively. The structure of the evaluation chart and the derivation of difficulty scores are explained, followed by a demonstration of analyzing a computer central processing unit. The limitations of the method and future extensions are outlined.  相似文献   
69.
Derbeko  Philip  Dolev  Shlomi  Gudes  Ehud 《Wireless Networks》2021,27(1):351-366
Wireless Networks - The privacy-preserving data release is an increasingly important problem in today’s computing. As the end devices collect more and more data, reducing the amount of...  相似文献   
70.
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