• Smart Structures and Systems
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• v.31 no.5
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• pp.455-467
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• 2023

Impact damper is a passive damping system that controls undesirable vibration with mass block impacting with stops fixed to the excited structure, introducing momentum exchange and energy dissipation. However, harmful momentum exchange may occur in the random excitation increasing structural response. Based on the mechanism of impact damping system, a semi-active impact damper (SAID) with controllable impact timing as well as a semi-active control strategy is proposed to enhance the seismic performance of engineering structures in this paper. Comparative experimental studies were conducted to investigate the damping performances of the passive impact damper and SAID. The extreme working conditions for SAID were also discussed and approaches to enhance the damping effect under high-intensity excitations were proposed. A numerical simulation model of SAID attached to a frame structure was established to further explore the damping mechanism. The experimental and numerical results show that the SAID has better control effect than the traditional passive impact damper and can effectively broaden the damping frequency band. The parametric studies illustrate the mass ratio and impact damping ratio of SAID can significantly influence the vibration control effect by affecting the impact force.

• Computers and Concrete
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• v.30 no.5
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• pp.323-337
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• 2022

This paper proposes a numerical model to simulate the rotational behavior of steel fiber in fresh cement-based materials in the presence of a magnetic field. The results indicate that as the aspect ratio of fiber increases, the required minimum magnetic field intensity to make fiber rotate in viscous fluid increases. The optimal magnetic field intensity is 0.03 T for aligning steel fiber in fresh cement-based materials to ensure that the applying time of the magnetic field can be conducted concurrently with the vibrating process to increase the aligning efficiency. The orientation factor of steel fiber in cement mortar can exceed 0.85 after aligning by 0.03 T of the uniform magnetic field. When the initial angle of the fiber to the magnetic field direction is less than 10°, the magnetic field less than 0.03 T cannot make the fiber overcome the yield stress of fluid to rotate. The coarse aggregate in steel fiber-reinforced concrete is detrimental to the rotation and alignment of the steel fiber. But the orientation factor of ASFRC under the 0.03T of the magnetic field can also exceed 0.8, while the orientation factor of SFRC without magnetic field application is around 0.6.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.815-819
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• 2023

Currently, China's urban space is gradually changing from gradual development to inventory transformation. The planning and development goals of urban communities have also shifted from material space construction to the direction of sustainable development of humanities and society. Currently, community planning and construction at a single latitude, which focuses on residential life, overlooks the multidimensional elements of community life production, causing many problems such as cold relationships between communities and difficulties in forming relationships between humans and the environment. Therefore, this article re-recognizes the sociality of the community in the continuous unification of the community in time and space, clarifies the central and private aspects of the community, and re-explores the dynamic creation and methods of the community as the starting point of daily life.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.769-773
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• 2015

Fibulin-5 has recently been considered as a potential tumor suppressor in human cancers. Several studies have shown that it is down-regulated in a variety of tumor types and inhibits tumor growth and metastasis. This study was aimed to investigate the clinical significance of fibulin-5 in glioma and its role in cell proliferation and invasion. We found that the expression of fibulin-5 in glioma tissues was significantly lower than those in normal brain (NB) tissues. Negative expression was significantly correlated with advanced clinical stage (grade III+IV). Furthermore, Fibulin-5 negative expression was correlated with a shorter overall survival of glioma patients. Multivariate Cox repression analysis indicated that fibulin-5 was an independent factor for predicting overall survival of glioma patients. Overexpression obviously inhibited cell proliferation in U251 and U87 cells. Furthermore, it significantly reduced the number of migrating and invading glioma cells. In conclusion, impaired expression of fibulin-5 is correlated with the advanced tumor stage in glioma. Otherwise, Fibulin-5 is an independent prognostic marker for predicting overall survival of glioma patients. Mechanistically, it may function as a tumor suppressor via inhibiting cell proliferation and invasion in gliomas.

• Journal of the Korean Chemical Society
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• v.54 no.4
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• pp.429-436
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• 2010

A series of some biologically active halogenopurines were synthesized from commercially available guanine (1). The reaction of guanine with acetic anhydride yielded 2,9-diacetylguanine (2-1) by acetylation reaction. Further treatment of 2-1 with $POCl_3$ by PEG-2000 phase transfer catalysis furnished the important compound 3a, then 2-amino-6-halogenopurines (3b-d) were obtained through chlorine-exchange halogenations between KX and 3a by TPPB phase transfer catalyst. Further, 2-halogenopurines (2-2a-d, 4-2a-d, 5a-d) were efficiently prepared from 2-amino-6-substituted purines (1, 3a, 4-1) via a diazotization catalyzed by their corresponding CuX, and some new compounds 2-2a, 2-2c, 2-2d, 4-2c, 4-2d, 5b, 5c and 5d have been discovered. The structures of synthesized compounds were mainly established on the basis of their elemental analysis, $^1H$ NMR, as well as their mass spectral data. All the title compounds were screened for their antifungal activities, and some of the compounds showed promising activity.

• The Journal of Advanced Prosthodontics
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• v.11 no.5
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• pp.286-296
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• 2019

PURPOSE. The aim was to study the masking ability of high-translucency monolithic zirconia and provide guidance in selecting resin luting cements in order to mask discolored substrates. MATERIALS AND METHODS. 160 high-translucency zirconia specimens were divided into 32 groups depending on their thickness and shades. Using five shades of try-in paste, the specimens were luted onto the substrates (Co-Cr, precious-metal, opaque porcelain-sintered Co-Cr, opaque porcelain-sintered precious-metal, and 5M3-shade zirconia). All CIELAB color parameters were measured and statistically analyzed. RESULTS. Zirconia shade and thickness and try-in paste shade affected CIELAB color parameters (P=.000) in different substrates groups, and there were interactions among these factors (P=.000). All five try-in paste shades can be chosen to achieve ${\Delta}E$ values of zirconia with 1.2 - 1.5 mm for masking dark-tooth-like 5M3-shade and zirconia with 1.5 mm for masking precious-metal groups < 2.6. Only suitable try-in paste shades were used, can ${\Delta}E$ values that less than 2.6 be achieved when applied translucent monolithic zirconia with 0.7-1.0 mm for masking dark-tooth-like 5M3-shade and zirconia with 0.7 - 1.2 mm for masking precious-metal groups. CONCLUSION. Choosing suitable resin cement shades is necessary for high-translucency monolithic zirconia to achieve ideal masking ability (${\Delta}E$ < 2.6) on the dark-tooth.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.464-472
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• 2022

An endo-polygalacturonase (endo-PGase) exhibiting excellent performance during acidic fruit juice production would be highly attractive to the fruit juice industry. However, candidate endo-PGases for this purpose have rarely been reported. In this study, we expressed a gene from Penicillium oxalicum in Pichia pastoris. The recombinant enzyme PoxaEnPG28C had an optimal enzyme activity at pH 4.5 and 45℃ and was stable at pH 3.0-6.5 and < 45℃. The enzyme had a specific activity of 4,377.65 ± 55.37 U/mg towards polygalacturonic acid, and the K_m and V_max values of PoxaEnPG28C were calculated as 1.64 g/l and 6127.45 U/mg, respectively. PoxaEnPG28C increased the light transmittance of orange, lemon, strawberry and hawthorn juice by 13.9 ± 0.3%, 29.4 ± 3.8%, 95.7 ± 10.2% and 79.8 ± 1.7%, respectively; it reduced the viscosity of the same juices by 25.7 ± 1.6%, 52.0 ± 4.5%, 48.2 ± 0.7% and 80.5 ± 2.3%, respectively, and it increased the yield of the juices by 24.5 ± 0.7%, 12.7 ± 2.2%, 48.5 ± 4.2% and 104.5 ± 6.4%, respectively. Thus, PoxaEnPG28C could be considered an excellent candidate enzyme for acidic fruit juice production. Remarkably, fruit juice production using hawthorn as an material was reported for the first time.

• Journal of Veterinary Clinics
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• v.23 no.1
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• pp.65-68
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• 2006

Two cases of canine intervertebral disc disease (IVDD) were treated twice a week with injection-acupuncture (injection-AP) using 0.1 ml/acupoint. In case 1, a paralysed dog with cervical intervertebral disc disease (C3-C4), was submitted to injection-AP with dexamethasone (1 mg/ml) at session 1-2 and thiamine (25 mg/ml) at session 3-5. Injected acupoints included GV-16, GB-20, BL-10, LU-7, LI-4 and SI-6. The acupoints GV-6, GV-20 and SP-6 were added at session 2-5. Trigger point (TP) therapy with 0.2 ml of 2% lidocaine was used in session 3-5 at TP in the infraspinatus and triceps muscles. Treatment was stopped when paralysis disappeared after 5 injection-AP treatments; there were no recurrent symptoms in the follow-up period of 5 months. In case 2, an ataxic dog with lumbar IVDD (L1-L2), was submitted to injection-AP with dexamethasone at session 1 and 2 and thiamine at session 3-4. Injected acupoints included GV-6 as the main point, ST-36, GB-30, ST-40, GB-34, ST-41 and BL-40. TP therapy with 0.2 ml of 2% lidocaine was used at TP in the ileocostorum lumborum and quadriceps muscles. Treatment was stopped when ataxia disappeared after 4 treatments; there were no recurrent symptoms In the fallow-up period of 5 months. Injection-AP using dexamethasone and thiamine, combined with TP therapy using lidocaine, effectively alleviate the symptoms of canine cervical and lumbar IVDD.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.183-188
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• 2005

Effects of co-solvent polarity, citric acid, pressure, temperature, run time, and co-solvent ratio on extraction of major flavonoids from Lonicera Flos were investigated using supercritical fluid $CO_{2}(SF-CO_{2})$. HPLC analysis revealed addition of pure methanol resulted in low extraction yield of major flavonoids, luteoloin (Lu), Quercetin (Qu), Apigenin (Ap). Under same condition, as co-solvent polarity increased, yields of major flavonoids increased gradually, At optimum co-solvent extraction condirion of 60% aqueous methanol (10%, v/v), yields of Lu, Qu, and Ap were 42.09, 28.18, and 3.49 mg/100 g, respectively. Addition of citric acid to 60% aqueous methanol gave higher, with addition of 1% citrie acid resulting in highest yields of 63.2 (Lu), 39.35 (Qu), and 5.79 (Ap) mg/100 g. Optimum extraction conditions of major flavonoids were 200 bar, $50^{\circ}C$, 60 min, and $CO_{2}$-methanol-water(20: 1.8: 1.2).

• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.898-904
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• 2014

The stability of Bacillus licheniformis alpha-amylase (BLA) under acid condition was enhanced through direct evolution using the error-prone polymerase chain reaction. One beneficial mutation site, H281I, was obtained in BLA. The specific activity of H281I was 161/352 U/mg, which was 62.6/27.5% higher than that of the wild-type (WT) (99/276 U/mg) at pH 4.5/6.5 and $95^{\circ}C$. The pH optimum for H281I was decreased about 1 unit, whereas no significant changes of optimum temperature and thermostability were observed compared with the wild type (WT). The $k_{cat}/K_m$ value of H281I was 1.7-/1.4-fold higher at pH 4.5/6.5, respectively, than that of WT. The structure model analysis indicated that the H281I mutation altered the predicted interaction between the amino acid residues at 281 and 273, thus creating a conducive local environment for substrate binding, as reflected by its decreased $K_m$, and consequently increased the specific activity.