• Advanced Composite Materials
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• 제18권2호
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• pp.95-103
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• 2009

Composites can be designed to have special properties, and even such properties that are difficult to find in nature. We propose a simple approach to realize negative expansion upon wetting, i.e., contraction upon wetting, using swelling materials. The key parameters in one-dimensional case are investigated, and the possible configurations for two and three-dimensional cases are presented. The feasibility is demonstrated through a simple test.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.806-813
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• 2012

Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제18권5호
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• pp.1116-1121
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• 2014

Mesh structure is one of typical interconnection networks, and it is used in the part of VLSI circuit design. Torus and Hyper-Torus are advanced interconnection networks in the part of diameter and fault-tolerance of mesh structure. In this paper, we will analyze embedding between Torus and Hyper-Torus networks. We will show T(4k,2l) can be embedded into QT(m,n) with dilation 5, congestion 4, expansion 1. And QT(m,n) can be embedded into T(4k,2l) with dilation 3, congestion 3, expansion 1.

• Transactions of the Korean Society of Automotive Engineers
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• 제11권4호
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• pp.196-203
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• 2003

This study was performed to design the optimal block type expansion valve through analyzing the characteristics of the block type expansion valve in automotive air conditioning system using HFC-134a. Because an alternative refrigerant (HFC-l34a) is being used instead of CFC-12 for automotive air conditioning system, newly designed air conditioning components are necessary due to changes in characteristics. The performance tests were accomplished through the test bench, that is manufactured based on the study. And then it was carried out to measure the variation of temperature and pressure at each part of the air conditioning system according to the compressor speed.

• Journal of Periodontal and Implant Science
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• 제48권3호
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• pp.152-163
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• 2018

Purpose: To determine whether the swelling and mechanical properties of osmotic self-inflating expanders allow or not the induction of intraoral soft tissue expansion in dogs. Methods: Three different volumes (0.15, 0.25, and 0.42 mL; referred to respectively as the S, M, and L groups) of soft tissue expanders (STEs) consisting of a hydrogel core coated with a silicone-perforated membrane were investigated in vitro to assess their swelling behavior (volume swelling ratio) and mechanical properties (tensile strength, tensile strain). For in vivo investigations, the STEs were subperiosteally inserted for 4 weeks in dogs (n=5). Soft tissue expansion was clinically monitored. Histological analyses included the examination of alveolar bone underneath the expanders and thickness measurements of the surrounding fibrous capsule. Results: The volume swelling ratio of all STEs did not exceed 5.2. In tensile mode, the highest mean strain was registered for the L group ($98.03{\pm}0.3g/cm$), whereas the lowest mean value was obtained in the S group ($81.3{\pm}0.1g/cm$), which was a statistically significant difference (P<0.05). In addition, the S and L groups were significantly different in terms of tensile strength ($1.5{\pm}0.1g/cm$ for the S group and $2.2{\pm}0.1g/cm$ for the L group, P<0.05). Clinical monitoring showed successful dilatation of the soft tissues without signs of inflammation up to 28 days. The STEs remained volumetrically stable, with a mean diameter in vivo of 6.98 mm, close to the in vitro post-expansion findings (6.69 mm). Significant histological effects included highly vascularized collagen-rich fibrous encapsulation of the STEs, with a mean thickness of $0.67{\pm}0.12mm$. The bone reaction consisted of resorption underneath the STEs, while apposition was observed at their edges. Conclusions: The swelling and mechanical properties of the STEs enabled clinically successful soft tissue expansion. A tissue reaction consisting of fibrous capsule formation and bone loss were the main histological events.

• Smart Structures and Systems
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• 제10권4_5호
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• pp.485-499
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• 2012

Mode shape expansion is useful in structural dynamic studies such as vibration based structural health monitoring; however most existing expansion methods can not consider the modelling errors in the finite element model and the measurement uncertainty in the modal properties identified from vibration data. This paper presents a reliable approach for expanding mode shapes with consideration of both the errors in analytical model and noise in measured modal data. The proposed approach takes the perturbed force as an unknown vector that contains the discrepancies in structural parameters between the analytical model and tested structure. A regularisation algorithm based on the Tikhonov solution incorporating the L-curve criterion is adopted to reduce the influence of measurement uncertainties and to produce smooth and optimised expansion estimates in the least squares sense. The Canton Tower benchmark problem established by the Hong Kong Polytechnic University is then utilised to demonstrate the applicability of the proposed expansion approach to the actual structure. The results from the benchmark problem studies show that the proposed approach can provide reliable predictions of mode shape expansion using only limited information on the operational modal data identified from the recorded ambient vibration measurements.

• Archives of Pharmacal Research
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• 제15권3호
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• pp.234-238
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• 1992

Using cell-free extract of Lysobacter lactamgenus, enzymatic conversion of $\delta$-L-($\alpha$-aminoadiphyl)-L-cysteinyl-D-valine (ACV) the first substrate of $\beta$-lactam biosynthesis, into antibiotic compounds was attempted. In high performance liquid chromatographic (HPLC) analysis, the biosynthetic intermediates for cephalosporin antibiotics including isopenicillin N, deacetoxycephalosporin C, deacetylcephalosporin C and unknown cephem compound were detected in reaction mixtures. It implies that cephabacin compounds from L lactamgenus could be produced by biosynthetic routes through penicillin ring formation and its expansion to cephalosporin ring, likely as cephalosporin C from Cephalosporium or cephamycin C from Streptomyces. Among biosynthetic enzyme in cell-free extract, the ring formation activity (isopenicillin N synthetase activity) was separated in 50-60% of ammonium sulfate fraction, and ring expansion activity (deacetoxycephalosporin C synthetase activity) was found to be in 40-50% fraction. The partially purified isopenicillin N synthetase could convert as much as 90% ACV to isopenicillin N during 6-hour reaction.

• The Korean Journal of Physiology
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• 제28권2호
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• pp.225-231
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• 1994

The present study was undertaken to investigate the role of endogenous nitric oxide in renin release under different physiological conditions. In the first series of experiments, renin release was either inhibited by acute volume-expansion (VE) or stimulated by clipping one renal artery in the rat. VE was induced by intravenous infusion of saline (0.9% NaCl) up to 5% of the body weight over 45 min under thiopental (50 mg/kg, IP) anesthesia. VE caused a decrease of plasma renin concentration (PRC). With $N^G-nitro-L-arginine$ methyl ester $(L-NAME,\;5\;{\mu}g/kg\;per\;min)$ superadded to VE, PRC decreased further. The magnitude of increase in plasma atrial natriuretic peptide levels following VE was not affected by the L-NAME. In two-kidney, one clip rats, L-NAME-supplementation resulted in a decrease, and L-arginine-supplementation an increase of PRC. Plasma atrial natriuretic peptide levels were significantly lower in the L-arginine group than in the control. Blood pressure did not differ among the L-NAME, L-arginine, and control groups. In another series of experiments, the renin response to a blockade of NO synthesis was examined using in vitro preparations from isolated renal cortex. L-NAME significantly increased basal renin release, although it was without effect on the isoproterenol-stimulated release. These findings suggest that endogenous nitric oxide significantly contributes to the renin release. Since many factors may affect the renin release in vivo, an interaction between NO and renin under various pathophysiological states is to be further defined.

• Journal of Digital Convergence
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• 제16권8호
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• pp.301-309
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• 2018

The purpose of this study was to investigate the immediate effect of lumbar support and ischial pad on neck, trunk angle and chest expansion for stroke patients using wheelchair. Fifteen stroke patients were measured repeatedly when a lumbar support using(L support), a Ischial pad using(I Pad), a Lumbar support with ischial pad using(L With I), and non using it(Non using). The measurement of the neck and trunk angle was confirmed using a mobile phone camera, and chest expansion was performed using a tapeline. L With I increased significantly in neck and trunk angle and lower chest expansion than non using. This study shows that simultaneous use of lumbar support and ischial pad for stroke patients using wheelchair can increase the neck and trunk angle, chest expansion immediately. Future studies will need to identify more long-term changes by continuing intervention with more subjects.

• Proceedings of the Korean Nuclear Society Conference
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.404-404
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• 1996

In order to ensure a concrete expansion anchor is suitable for a given application, the load resistance behavior of the anchor must be known. ASTM E488 provides a standard method of testing expansion anchors for static and dynamic loads. Due to the many types of anchors available commercially and the large variability of applications, the ASTM does not delineate all details or requirements necessary to comprehensively determine the dynamic load behavior of concrete expansion anchors. A test program is presented in this paper which was developed and implemented to determine the cyclic load behavior of wedge-type concrete expansion anchors. Test results are also presented along with a discussion of the behavior of anchors, and their suitability for use.