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排序方式: 共有588条查询结果,搜索用时 15 毫秒
91.
The sensitivity of a simple root of a polynominal is finite and well defined. For a multiple root, however, the existing definition becomes infinite, even when the root displacements remain finite. In this letter, a well behaved function is proposed to define a multiple-root sensitivity. It is also shown that the new definition, which degenerates to the conventional definition under a special condition, is a meaningful measure of actual root displacements. 相似文献
92.
Quinton L Le Caer JP Phan G Ligny-Lemaire C Bourdais-Jomaron J Ducancel F Chamot-Rooke J 《Analytical chemistry》2005,77(20):6630-6639
The standard analytical procedure for screening the proteomic profile of a venom often relies on an appropriate combination of sample extraction, electrophoresis, reversed-phase high-performance liquid chromatography, mass spectrometry, and Edman degradation. We present in this study a new approach for venom screening based on Fourier transform mass spectrometry (FTMS) analysis directly on the crude venom. The venom chosen is a unique sample from Atractaspis irregularis, a species never studied at the molecular level previously. This snake belongs to the Atractaspidae family that is known to produce highly toxic venoms containing endothelin-like peptides called sarafotoxins (SRTXs). Nanoelectrospray-FTMS spectrum of the crude venom allowed the identification of 60 distinct compounds with molecular masses from 600 to 14,000 Da, which would have been impossible without the resolution of this kind of instrument. De novo sequencing within the entire venom confirmed the sequences of two new families of sarafotoxins, whose precursors had been cloned, and allowed the characterization of a third one. One particularly interesting point was that the propolypeptides appeared processed not in one unique compound, but rather in different length molecules ranging from 15 for the shorter to 30 amino acids for the longer. Moreover, our results clearly establish that in the case of A. irregularis only one copy of mature sarafotoxin emerges from each precursor, which is a totally different organization in comparison of other precursors of SRTXs. 相似文献
93.
BE Sumpio SM Phan FP Gasparro LI Deckelbaum 《Canadian Metallurgical Quarterly》1993,17(6):1010-6; discussion 1016-8
PURPOSE: Restenosis after balloon angioplasty or the intimal hyperplasia occurring at distal anastomoses of bypass grafts severely limits the long-term therapy for peripheral vascular disease. The aim of this study was to evaluate the application of psoralen photochemotherapy with ultraviolet A (UVA)-activated 8-methoxypsoralen (8-MOP) to suppress smooth muscle cell (SMC) proliferation in vitro by the formation of 8-MOP-DNA monoadducts and interstrand cross-links to inhibit DNA synthesis. METHODS: Bovine aorta SMC (2 x 10(4)/cm2) were treated with 8-MOP (0 to 1000 ng/ml) for 30 minutes, followed by UVA (2 joule/cm2) to determine the dose of 8-MOP and UVA that inhibits SMC proliferation. RESULTS: The results show that 8-MOP in the range 30 to 1000 ng/ml in combination with 2 joule/cm2 UVA inhibited SMC proliferation by 40% to 60% 3 days after treatment. In time course studies the growth of SMC treated with 100 ng/ml 8-MOP and 2 joule/cm2 UVA were monitored over 5 days, and this regimen was found to be cytostatic. SMC viability was confirmed by trypan blue exclusion. CONCLUSIONS: Our studies suggest that 8-MOP/UVA photochemotherapy may represent a novel approach to the control of localized SMC proliferation. 相似文献
94.
95.
Phan Han Duy Ellis Kirsten Barca Jan Carlo Dorin Alan 《Neural computing & applications》2020,32(2):567-588
Neural Computing and Applications - Parameter settings for nature-inspired optimization algorithms are essential for their effective performance. Evolutionary algorithms and swarm intelligence... 相似文献
96.
Truong Phuong Phan Alex Truong Buu Suen Benjamin Melles Gerrit Talke Frank 《Microsystem Technologies》2020,26(11):3403-3407
Microsystem Technologies - A low-cost, self-imaging smartphone attachment has been developed for remote slit lamp examination of the human eye. The device is designed with off-the-shelf optical... 相似文献
97.
Identifying compromised accounts on online social networks that are used for phishing attacks or sending spam messages is still one of the most challenging problems of cyber security. In this research, the authors explore an artificial neural network‐based language model to differentiate the writing styles of different users on short text messages. In doing so, the aim is to be able to identify compromised user accounts. The results obtained indicate that one can learn the language model on one dataset and can generalize it to different datasets to identify users with high accuracy and low false alarm rates without any modification to the language model. 相似文献
98.
In this paper, we analyze the tradeoff between outage probability (OP) and intercept probability (IP) for a multi‐hop relaying scheme in cognitive radio (CR) networks. In the proposed protocol, a multi‐antenna primary transmitter (PT) communicates with a multi‐antenna primary receiver (PR), using transmit antenna selection (TAS) / selection combining (SC) technique, while a secondary source attempts to transmit its data to a secondary destination via a multi‐hop approach in presence of a secondary eavesdropper. The secondary transmitters such as source and relays have to adjust their transmit power to satisfy total interference constraint given by PR. We consider an asymmetric fading channel model, where the secondary channels are Rician fading, while the remaining ones experience the Rayleigh fading. Moreover, an optimal interference allocation method is proposed to minimize OP of the primary network. For the secondary network, we derive exact expressions of end‐to‐end OP and IP which are verified by Monte Carlo simulations. 相似文献
99.
Toan Dinh Thanh Nguyen Hoang‐Phuong Phan Tuan‐Khoa Nguyen Van Thanh Dau Nam‐Trung Nguyen Dzung Viet Dao 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(14)
Stretchable and wearable sensor technology has attracted significant interests and created high technological impact on portable healthcare and smart human–machine interfaces. Wearable electromechanical systems are an important part of this technology that has recently witnessed tremendous progress toward high‐performance devices for commercialization. Over the past few years, great attention has been paid to simultaneously enhance the sensitivity and stretchability of the electromechanical sensors toward high sensitivity, ultra‐stretchability, low power consumption or self‐power functionalities, miniaturisation as well as simplicity in design and fabrication. This work presents state‐of‐the‐art advanced materials and rational designs of electromechanical sensors for wearable applications. Advances in various sensing concepts and structural designs for intrinsic stretchable conductive materials as well as advanced rational platforms are discussed. In addition, the practical applications and challenges in the development of stretchable electromechanical sensors are briefly mentioned and highlighted. 相似文献
100.
Aung Than Phan Khanh Duong Ping Zan Junjie Liu Melvin Khee‐Shing Leow Peng Chen 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(31)
Obesity is a serious epidemic health problem that can cause many other diseases including type 2 diabetes and cardiovascular diseases. Current approaches to combat obesity suffer from low effectiveness and adverse side effects. Here, a new self‐administrable and minimally invasive transdermal drug delivery strategy for home‐based long‐term treatment of obesity and other diseases is developed. Specifically, ultrathin, core‐shelled, and lance‐shaped polymeric drug reservoirs (micro‐lances [MLs]) are readily fabricated by a thermal pressing molding method and totally implanted into subcutaneous fat by lancing through the skin. Using a diet‐induced obese mouse model, it is shown that the development of obesity and associated metabolic disorders is effectively inhibited by applying therapeutic core‐shelled MLs once every 2 weeks. The outstanding therapeutic effects are attributable to highly localized and biphasic drug release, as well as combination therapy based on browning transformation of white fat and enhanced insulin sensitivity. 相似文献