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排序方式: 共有508条查询结果,搜索用时 15 毫秒
1.
Vancha Harish Effi Haque Magdalena
miech Hiroaki Taniguchi Sarah Jamieson Devesh Tewari Anupam Bishayee 《International journal of molecular sciences》2021,22(9)
Xanthohumol (XH) is an important prenylated flavonoid that is found within the inflorescence of Humulus lupulus L. (Hop plant). XH is an important ingredient in beer and is considered a significant bioactive agent due to its diverse medicinal applications, which include anti-inflammatory, antimicrobial, antioxidant, immunomodulatory, antiviral, antifungal, antigenotoxic, antiangiogenic, and antimalarial effects as well as strong anticancer activity towards various types of cancer cells. XH acts as a wide ranging chemopreventive and anticancer agent, and its isomer, 8-prenylnaringenin, is a phytoestrogen with strong estrogenic activity. The present review focuses on the bioactivity of XH on various types of cancers and its pharmacokinetics. In this paper, we first highlight, in brief, the history and use of hops and then the chemistry and structure–activity relationship of XH. Lastly, we focus on its prominent effects and mechanisms of action on various cancers and its possible use in cancer prevention and treatment. Considering the limited number of available reviews on this subject, our goal is to provide a complete and detailed understanding of the anticancer effects of XH against different cancers. 相似文献
2.
We present uniaxial tensile test results for 30–50 nm thick freestanding aluminum films. Young’s modulus and ductility were found to decrease monotonically with grain size. Reverse Hall–Petch behavior was observed with no appreciable room temperature creep. Non-linear elasticity with small irreversible deformation was observed for 50 nm thick specimens. 相似文献
3.
The feasibility of applying a chemical method based on the formation of 2-alkylcyclobutanone to samples of irradiated soft cheese (Brie and Camembert) was investigated. Significant quantities of 2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB) were detected in both types of irradiated cheese and are proposed as qualitative markers. Other members of the cyclobutanone family (decyl- and tetradecenyl-) are also thought to be present but could not be substantiated due to a lack of authentic standards. These compounds were absent from the unirradiated samples. Results also show a significant linear relationship between the irradiation dose (1 to 8 kGy) and the amount of DCB and TCB detected in the cheese. 相似文献
4.
5.
P. Ravirajan S.A. Haque J.R. Durrant D.D.C. Bradley J. Nelson 《Advanced functional materials》2005,15(4):609-618
We report a study of the effects of polymer optoelectronic properties on the performance of photovoltaic devices consisting of nanocrystalline TiO2 and a conjugated polymer. Three different poly(2‐methoxy‐5‐(2′‐ethylhexoxy)‐1,4‐phenylenevinylene) (MEH‐PPV)‐based polymers and a fluorene–bithiophene copolymer are compared. We use photoluminescence quenching, time‐of‐flight mobility measurements, and optical spectroscopy to characterize the exciton‐transport, charge‐transport, and light‐harvesting properties, respectively, of the polymers, and correlate these material properties with photovoltaic‐device performance. We find that photocurrent is primarily limited by the photogeneration rate and by the quality of the interfaces, rather than by hole transport in the polymer. We have also studied the photovoltaic performance of these TiO2/polymer devices as a function of the fabrication route and device design. Including a dip‐coating step before spin‐coating the polymer leads to excellent polymer penetration into highly structured TiO2 networks, as was confirmed through transient optical measurements of the photoinduced charge‐transfer yield and recombination kinetics. Device performance is further improved for all material combinations studied, by introducing a layer of poly(ethylene dioxythiophene) (PEDOT) doped with poly(styrene sulfonic acid) (PSS) under the top contact. Optimized devices incorporating the additional dip‐coated and PEDOT:PSS layers produced a short‐circuit current density of about 1 mA cm–2, a fill factor of 0.50, and an open‐circuit voltage of 0.86 V under simulated AM 1.5 illumination (100 mW cm–2, 1 sun). The corresponding power conversion efficiency under 1 sun was ≥ 0.4 %. 相似文献
6.
M.N. Haque 《Cement and Concrete Research》1980,10(1):13-22
The paper briefly reviews the concepts of dry lean concrete (DLC), roller compacted concrete (RCC) and Econocrete and their possible applications for the construction of subbase in pavement, concrete gravity dam and fill etc. The effects of differing quantities of fraction passing 75 μm on the strength and workability of concrete are reported. The 28 days compressive strength of all-in-aggregate concrete decreased at 1 and 5% silt contents whereas it increased at 10% silt as compared to the silt free concrete exposed to continuous air curing. It was observed that the water curing of all-in-aggregate concrete dramatically improved the compressive strength of the concrete as compared to the air curing. It is also reported that the variations in the pulse velocity on the concrete with differing silt content and curing regimes followed similar pattern of that of the variations in the compressive strength. 相似文献
7.
Q. Ahsan A. S. M. A. Haseeb E. Haque J. P. Celis 《Journal of Materials Engineering and Performance》2003,12(3):304-311
This paper describes an investigation on the failure of a large leaded bronze bearing that supports a nine-ton roller of a
plastic calendering machine. At the end of the normal service life of a good bearing, which lasted for seven years, a new
bearing was installed. However the new one failed catastrophically within a few days, generating a huge amount of metallic
wear debris and causing pitting on the surface of the cast iron roller. Following the failure, samples were collected from
both good and failed bearings. The samples were analyzed chemically and their microstructures examined. Both samples were
subjected to accelerated wear tests in a laboratory type pin-on-disk apparatus. During the tests, the bearing materials acted
as pins, which were pressed against a rotating cast iron disk. The wear behaviors of both bearing materials were studied using
weight loss measurement. The worn surfaces of samples and the wear debris were examined by light optical microscope, scanning
electron microscope, and energy-dispersive x-ray microanalyzer. It was found that the laboratory pin-on-disk wear data correlated
well with the plant experience. It is suggested that the higher lead content (∼18%) of the good bearing compared with 7% lead
of the failed bearing helped to establish a protective transfer layer on the worn surface. This transfer layer reduced metal-to-metal
contact between the bearing and the roller and resulted in a lower wear rate. The lower lead content of the failed bearing
does not allow the establishment of a well-protected transfer layer and leads to rapid wear. 相似文献
8.
Genetic algorithm-based motion estimation schemes play a significant role in improving the results of H.264/AVC standardization efforts when addressing conversational and non-conversational video applications. In this paper, we present a robust motion estimation scheme that uses a noble genetic trail bounded approximation (GTBA) approach to speed up the encoding process of H.264/AVC video compression and to reduce the number of bits required to code frame. The proposed algorithm is utilized to enhance the fitness function strength by integrating trail information of motion vector and sum of absolute difference (SAD) information into a fitness function. Experimental results reveal that the proposed GTBA resolves conflict obstacles with respect to both the number of bits required to code frames and the execution time for estimation. 相似文献
9.
Automated audio segmentation and classification play important roles in multimedia content analysis. In this paper, we propose an enhanced approach, called the correlation intensive fuzzy c-means (CIFCM) algorithm, to audio segmentation and classification that is based on audio content analysis. While conventional methods work by considering the attributes of only the current frame or segment, the proposed CIFCM algorithm efficiently incorporates the influence of neighboring frames or segments in the audio stream. With this method, audio-cuts can be detected efficiently even when the signal contains audio effects such as fade-in, fade-out, and cross-fade. A number of audio features are analyzed in this paper to explore the differences between various types of audio data. The proposed CIFCM algorithm works by detecting the boundaries between different kinds of sounds and classifying them into clusters such as silence, speech, music, speech with music, and speech with noise. Our experimental results indicate that the proposed method outperforms the state-of-the-art FCM approach in terms of audio segmentation and classification. 相似文献
10.
Haque Tipu Sultan Chakraborty Avishek Alam Shariful 《Knowledge and Information Systems》2023,65(9):3695-3724
Knowledge and Information Systems - Generalized spherical fuzzy number (GSFN) is an extension of spherical fuzzy number (SFN) which deals the uncertainties involved in the real-life problems in... 相似文献