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91.
Im Deok Jung Min Kook Cho Kong Myeong Bae Sang Min Lee Phill Gu Jung Ho Kyung Kim Sung Sik Kim Jong Soo Ko 《ETRI Journal》2008,30(5):747-749
We introduce a pixel‐structured scintillator realized on a flexible polymeric substrate and demonstrate its feasibility as an X‐ray converter when it is coupled to photosensitive elements. The sample was prepared by filling Gd2O2S:Tb scintillation material into a square‐pore‐shape cavity array fabricated with polyethylene. For comparison, a sample with the conventional continuous geometry was also prepared. Although the pixelated geometry showed X‐ray sensitivity of about 58% compared with the conventional geometry, the resolving power was improved by about 70% above a spatial frequency of 3 mm?1. The spatial frequency at 10% of the modulation‐transfer function was about 6 mm?1. 相似文献
92.
Multicasting is a useful communication method in wireless mesh networks (WMNs). Many applications in WMNs require efficient
and reliable multicast communications, i.e., high delivery ratio with low overhead among a group of recipients. In spite of
its significance, little work has been done on providing such multicast service in multi-channel WMNs. Traditional multicast
protocols for wireless and multi-hop networks tend to assume that all nodes, each of which is equipped with a single interface,
collaborate on the same channel. This single-channel assumption is not always true, as WMNs often provide nodes with multiple
interfaces to enhance performance. In multi-channel and multi-interface (MCMI) WMNs, the same multicast data must be sent
multiple times by a sender node if its neighboring nodes operate on different channels. In this paper, we try to tackle the
challenging issue of how to design a multicast protocol more suitable for MCMI WMNs. Our multicast protocol builds multicast
paths while inviting multicast members, and tries to allocate the same channel to neighboring members in a bottom-up manner.
By unifying fixed channels of one-hop multicast neighbors, the proposed algorithm can improve the performance such as reducing
multicast data transmission overhead and delay, while managing a successful delivery ratio. In order to prove such expectation
on the performance, we have implemented and evaluated the proposed solution on the real testbed having the maximum 24 nodes,
each of which is equipped with two IEEE 802.11a Atheros WLAN cards. 相似文献
93.
Joonho Shin Atanu Naskar Dongjoon Ko Semi Kim Kwang-sun Kim 《International journal of molecular sciences》2022,23(12)
Owing to the rapid spread of antibiotic resistance among Staphylococcus species, effective and low-risk alternatives to antibiotics are being actively searched. Thymol (THO), the most abundant component of the oil extracted from thyme, can be considered as a natural antibacterial alternative. However, the low antibacterial activity and non-selectivity of THO limit its usage as a universal anti-Staphylococcus agent. Herein, we report the bioconjugation of THO with ZnO nanoparticle (ZO), which resulted in the TZ nanocomposite (NC), as a potent and selective antibacterial agent against Staphylococcus species, particularly S. epidermidis. The cell-free supernatant (CFS) of ATCC 25923 cultures was employed for the production of TZ NC. Successful production of TZ NC was confirmed via X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and ultraviolet–visible (UV–Vis) studies. TZ NC had selective efficacy against Staphylococcus species, with MIC values 2–32-fold lower than THO. The antibacterial mechanisms of TZ NC are proposed to involve membrane rupture, suppression of biofilm formation, and modulation of new cell wall and protein-synthesis-associated cellular pathways. Its biocompatibility against HCT116 cells was also checked. Our findings suggest that the TZ nanocomposite could improve the selectivity and bactericidal activity of THO against target species. 相似文献
94.
Jiwon Kim Hyeoncheol Francis Son Sungmin Hwang Gyeongtaek Gong Ja Kyong Ko Youngsoon Um Sung Ok Han Sun-Mi Lee 《International journal of molecular sciences》2022,23(9)
Yarrowia lipolytica, the non-conventional yeast capable of high lipogenesis, is a microbial chassis for producing lipid-based biofuels and chemicals from renewable resources such as lignocellulosic biomass. However, the low tolerance of Y. lipolytica against furfural, a major inhibitory furan aldehyde derived from the pretreatment processes of lignocellulosic biomass, has restricted the efficient conversion of lignocellulosic hydrolysates. In this study, the furfural tolerance of Y. lipolytica has been improved by supporting its endogenous detoxification mechanism. Specifically, the endogenous genes encoding the aldehyde dehydrogenase family proteins were overexpressed in Y. lipolytica to support the conversion of furfural to furoic acid. Among them, YALI0E15400p (FALDH2) has shown the highest conversion rate of furfural to furoic acid and resulted in two-fold increased cell growth and lipid production in the presence of 0.4 g/L of furfural. To our knowledge, this is the first report to identify the native furfural detoxification mechanism and increase furfural resistance through rational engineering in Y. lipolytica. Overall, these results will improve the potential of Y. lipolytica to produce lipids and other value-added chemicals from a carbon-neutral feedstock of lignocellulosic biomass. 相似文献
95.
96.
In this work the method of response surfaces was used for the purpose of drawing up a mathematical model for the calculation
(forecasting) of the adhesion of a flame sprayed coating of powdered aluminum on S 235 JR steel. Experimental work was conducted
according to a fractional central-composite design at three levels. The adhesion of the coatings made with combinations of
input parameters of the procedure according to the experiment plan mentioned is measured in line with the EN 582 standard.
A mathematical model was derived describing the dependence of the experimentally obtained adhesion values on the input parameters
of the procedure. The possibility of analyzing the influence of the parameters on the adhesion for a certain combination of
input parameters has been presented with the use of perturbation plots. 相似文献
97.
A vehicle head-up display (HUD) has a semitransparent property that utilizes a method of projecting light onto the windshield. The semitransparent characteristic of the HUD generates continuous superimposition between the “HUD graphic” and “road environment events.” This study aims to determine the effects of HUD use on elderly driving. Two age groups (elderly, younger) performed tasks (speed monitoring, navigation) utilizing two types of display (HUD, head-down display) in two different circumstances (high superimposition level, low superimposition level). Subject performance was evaluated by having the subjects execute a secondary display task while performing a primary driving task with an eye-tracking task. In addition, the degree of driver visual distraction was verified through the measurement of display glance duration. The results showed that an increase in superimposition negatively affected driver glance duration independent of age. However, the use of HUD in low superimposition situations showed relative advantages with regard to display use independent of age. This study confirmed that the negative effects of HUD use need to be considered during the selection of HUD information and display location. In particular, this study verifies that special attention should be given to the negative effects of superimposition of text information for use by an elderly population. 相似文献
98.
The flash point is one of the most important properties of flammable liquids. This study proposes a support vector regression
(SVR) model to predict the flash points of 792 organic compounds from the DIPPR 801 database. The input variables of the model
consist of 65 different functional groups, logarithm of molecular weight and their boiling points in this study. Cross-validation
and particle swarm optimization were adopted to find three optimal parameters for the SVR model. Since the prediction largely
relies on the selection of training data, 100 training data sets were randomly generated and tested. Moreover, all of the
organic compounds used in this model were divided into three major classes, which are non-ring, aliphatic ring, and aromatic
ring, and a prediction model was built accordingly for each class. The prediction results from the three-class model were
much improved than those obtained from the previous works, with the average absolute error being 5.11–7.15 K for the whole
data set. The errors in calculation were comparable with the ones from experimental measurements. Therefore, the proposed
model can be implemented to determine the initial flash point for any new organic compounds. 相似文献
99.
Chia-Ling Ko Wen-Cheng Chen Jian-Chih Chen Ying- Hui Wang Chi-Jen Shih Yu-Chang Tyan Chun-Cheng Hung Jen-Chyan Wang 《Materials science & engineering. C, Materials for biological applications》2013,33(6):3537-3544
This study aims to evaluate further the performance of a platelet-rich plasma (PRP) additive incorporated with calcium phosphate bone cement (CPC) in vitro to prove its efficiency as bone graft substitutes and its compatibility to be incorporated into the CPC with other techniques in clinical restoration in vivo. The growth factor release ability and the osteogenic evaluation of PRP, CPC, and PRP/CPC testing groups with 5, 10, and 15 wt.% PRP were compared in vitro. Four groups were measured using non-decalcified staining methods in vivo, which include the testing group of 10 wt.% PRP/CPC selected from the evaluation in vitro, by using both the autograft with rabbit trabecular and CPC-only as comparison groups and the group without grafting material as the control sample. The results obtained through specimen immersion show that growth factor release and alkaline phosphatase activities after osteoprogenitor cell culture had a significantly better effect on 10 and 15 wt.% PRP/CPC than on the other groups in vitro. Analysis results suggest that PRP was still retained in the CPC matrix even after 32 days of immersion. The results in vivo show that the histology of the autograft bone and the control group without grafting material exhibited fibrous connective and adipose tissues, which obviously filled the created cavity even at nine weeks after the operation. Osteoregeneration was more successful in the PRP-additive group, which accumulated bone remodeling than in the other groups. In conclusion, CPC could be a potential carrier with adequate PRP additives that bear a therapeutic potential for enhanced bone tissue regeneration. 相似文献
100.