• Title/Summary/Keyword: translational research

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Research on a New Vision Test Chart Measuring Visual and Spatial Sense of Moire Fringes (무아레 무늬의 시각적 공간감각을 측정하는 시표로서의 가능성 조사)

  • Woo, Hyun Kyung;Lee, Seongjae;Jeong, Youn Hong
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.3
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    • pp.241-245
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    • 2010
  • Purpose: In this work we suggested a grating chart of vision test which could be used to measure the sense of distance and motion of object. Methods: A couple of gratings with periodic structure were fabricated. Through a lens the grating images showing geometrical shapes were projected on a vision test chart in order to form a new grating chart of vision test. In rotating and translating the gratings the examinee perceived the variation of position of gratings by the variation of the sense of distance and motion. Results: The results of the sense of distance and motion measured in rotating and translating the gratings showed the average errors of ~2.98% and ~1.73% at $\theta=15^{\circ}$ respectively compared to calculated values. Conclusions: The grating chart of vision test suggested in this work can be used as a new test chart that lets an examinee perceive a sense of distance and motion of object.

Dual mechanisms for the regulation of brain-derived neurotrophic factor by valproic acid in neural progenitor cells

  • Ko, Hyun Myung;Jin, Yeonsun;Park, Hyun Ho;Lee, Jong Hyuk;Jung, Seung Hyo;Choi, So Young;Lee, Sung Hoon;Shin, Chan Young
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.6
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    • pp.679-688
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    • 2018
  • Autism spectrum disorders (ASDs) are neurodevelopmental disorders that share behavioral features, the results of numerous studies have suggested that the underlying causes of ASDs are multifactorial. Behavioral and/or neurobiological analyses of ASDs have been performed extensively using a valid model of prenatal exposure to valproic acid (VPA). Abnormal synapse formation resulting from altered neurite outgrowth in neural progenitor cells (NPCs) during embryonic brain development has been observed in both the VPA model and ASD subjects. Although several mechanisms have been suggested, the actual mechanism underlying enhanced neurite outgrowth remains unclear. In this study, we found that VPA enhanced the expression of brain-derived neurotrophic factor (BDNF), particularly mature BDNF (mBDNF), through dual mechanisms. VPA increased the mRNA and protein expression of BDNF by suppressing the nuclear expression of methyl-CpG-binding protein 2 (MeCP2), which is a transcriptional repressor of BDNF. In addition, VPA promoted the expression and activity of the tissue plasminogen activator (tPA), which induces BDNF maturation through proteolytic cleavage. Trichostatin A and sodium butyrate also enhanced tPA activity, but tPA activity was not induced by valpromide, which is a VPA analog that does not induce histone acetylation, indicating that histone acetylation activity was required for tPA regulation. VPA-mediated regulation of BDNF, MeCP2, and tPA was not observed in astrocytes or neurons. Therefore, these results suggested that VPA-induced mBDNF upregulation was associated with the dysregulation of MeCP2 and tPA in developing cortical NPCs.

A new precast wall connection subjected to monotonic loading

  • Vaghei, Ramin;Hejazi, Farzad;Taheri, Hafez;Jaafar, Mohd Saleh;Ali, Abang Abdullah Abang
    • Computers and Concrete
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    • v.17 no.1
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    • pp.1-27
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    • 2016
  • Final construction project cost is significantly determined by construction rate. The Industrialized Building System (IBS) was promoted to enhance the importance of prefabrication technology rather than conventional methods in construction. Ensuring the stability of a building constructed by using IBS is a challenging issue. Accordingly, the connections in a prefabricated building have a basic, natural, and essential role in providing the best continuity among the members of the building. Deficiencies of conventional precast connections were observed when precast buildings experience a large induced load, such as earthquakes and other disasters. Thus, researchers aim to determine the behavior of precast concrete structure with a specific type of connection. To clarify this problem, this study investigates the capacity behavior of precast concrete panel connections for industrial buildings with a new type of precast wall-to-wall connection (i.e., U-shaped steel channel connection). This capacity behavior is compared with the capacity behavior of precast concrete panel connections for industrial buildings that used a common approach (i.e., loop connection), which is subjected to monotonic loading as in-plane and out-of-plane loading by developing a finite element model. The principal stress distribution, deformation of concrete panels and welded wire mesh (BRC) reinforcements, plastic strain trend in the concrete panels and connections, and crack propagations are investigated for the aforementioned connection. Pushover analysis revealed that loop connections have significant defects in terms of strength for in-plane and out-of-plane loads at three translational degrees of freedom compared with the U-shaped steel channel connection.

Effect of $Agrimonia$ $pilosa$ $Ledeb$ Extract on the Antinociception and Mechanisms in Mouse

  • Park, Soo-Hyun;Sim, Yun-Beom;Kang, Yu-Jung;Lee, Jin-Koo;Lim, Soon-Sung;Suh, Hong-Won
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.2
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    • pp.119-123
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    • 2012
  • In the present study, the antinociceptive profiles of $Agrimonia$ $pilosa$ $Ledeb$ extract were examined in ICR mice. $Agrimonia$ $pilosa$ $Ledeb$ extract administered orally (200 mg/kg) showed an antinociceptive effect as measured by the tail-flick and hot-plate tests. In addition, $Agrimonia$ $pilosa$ $Ledeb$ extract attenuated the writhing numbers in the acetic acid-induced writhing test. Furthermore, the cumulative nociceptive response time for intrathecal (i.t.) injection of substance P (0.7 ${\mu}g$) was diminished by $Agrimonia$ $pilosa$ $Ledeb$ extract. Intraperitoneal (i.p.) pretreatment with yohimbine (${\alpha}_2$-adrenergic receptor antagonist) attenuated antinociceptive effect induced by $Agrimonia$ $pilosa$ $Ledeb$ extract in the writhing test. However, naloxone (opioid receptor antagonist) or methysergide (5-HT serotonergic receptor antagonist) did not affect antinociception induced by $Agrimonia$ $pilosa$ $Ledeb$ extract in the writhing test. Our results suggest that $Agrimonia$ $pilosa$ $Ledeb$ extract shows an antinociceptive property in various pain models. Furthermore, this antinociceptive effect of $Agrimonia$ $pilosa$ $Ledeb$ extract may be mediated by ${\alpha}_2$-adrenergic receptor, but not opioidergic and serotonergic receptors.

Butyrate modulates bacterial adherence on LS174T human colorectal cells by stimulating mucin secretion and MAPK signaling pathway

  • Jung, Tae-Hwan;Park, Jeong Hyeon;Jeon, Woo-Min;Han, Kyoung-Sik
    • Nutrition Research and Practice
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    • v.9 no.4
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    • pp.343-349
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    • 2015
  • BACKGROUND/OBJECTIVES: Fermentation of dietary fiber results in production of various short chain fatty acids in the colon. In particular, butyrate is reported to regulate the physical and functional integrity of the normal colonic mucosa by altering mucin gene expression or the number of goblet cells. The objective of this study was to investigate whether butyrate modulates mucin secretion in LS174T human colorectal cells, thereby influencing the adhesion of probiotics such as Lactobacillus and Bifidobacterium strains and subsequently inhibiting pathogenic bacteria such as E. coli. In addition, possible signaling pathways involved in mucin gene regulation induced by butyrate treatment were also investigated. MATERIALS/METHODS: Mucin protein content assay and periodic acid-Schiff (PAS) staining were performed in LS174T cells treated with butyrate at various concentrations. Effects of butyrate on the ability of probiotics to adhere to LS174T cells and their competition with E. coli strains were examined. Real time polymerase chain reaction for mucin gene expression and Taqman array 96-well fast plate-based pathway analysis were performed on butyrate-treated LS174T cells. RESULTS: Treatment with butyrate resulted in a dose-dependent increase in mucin protein contents in LS174T cells with peak effects at 6 or 9 mM, which was further confirmed by PAS staining. Increase in mucin protein contents resulted in elevated adherence of probiotics, which subsequently reduced the adherent ability of E. coli. Treatment with butyrate also increased transcriptional levels of MUC3, MUC4, and MUC12, which was accompanied by higher gene expressions of signaling kinases and transcription factors involved in mitogen-activated protein kinase (MAPK) signaling pathways. CONCLUSIONS: Based on our results, butyrate is an effective regulator of modulation of mucin protein production at the transcriptional and translational levels, resulting in changes in the adherence of gut microflora. Butyrate potentially stimulates the MAPK signaling pathway in intestinal cells, which is positively correlated with gut defense.

Comparison of the marginal fit of milled yttrium stabilized zirconium dioxide crowns obtained by scanning silicone impressions and by scanning stone replicas

  • Yus, Estefania Aranda;Cantarell, Josep Maria Anglada;Alonso, Antonio Minarro
    • The Journal of Advanced Prosthodontics
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    • v.10 no.3
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    • pp.236-244
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    • 2018
  • PURPOSE. To determine the discrepancy in monolithic zirconium dioxide crowns made with computer-aided design and computer-aided manufacturing (CAD/CAM) systems by comparing scans of silicone impressions and of master casts. MATERIALS AND METHODS. From a Cr-Co master die of a first upper left molar, 30 silicone impressions were taken. The 30 silicone impressions were scanned with the laboratory scanner, thus obtaining 30 milled monolithic yttrium stabilized zirconium dioxide (YSZD) crowns (the silicone group). They were poured and the working models were scanned, obtaining 30 milled monolithic yttrium stabilized zirconium dioxide (YSZD) crowns (the plaster group). Three predetermined points were analyzed in each side of the crown (Mesial, Distal, Vestibular and Palatal), and the marginal fit was evaluated with SEM (${\times}600$). The response variable is the discrepancy from the master model. A repeated measures ANOVA with two within subject factors was performed to study significance of main factors and interaction. RESULTS. Mean marginal discrepancy was $22.42{\pm}35.65{\mu}m$ in the silicone group and $8.94{\pm}14.69{\mu}m$ in the plaster group. The statistical analysis showed significant differences between the two groups and also among the four aspects. Interaction was also significant (P=.02). CONCLUSION. The mean marginal fit values of the two groups were within the clinically acceptable values. Significant differences were found between the groups according to the aspects studied. Various factors influenced the accuracy of digitizing, such as the design, the geometry, and the preparation guidance, as well as the texture, roughness and the color of the scanned material.

Inverse Synthetic Aperture Radar Imaging Using Stepped Chirp Waveform (계단 첩 파형(Stepped Chirp Waveform)을 이용한 ISAR 영상 형성)

  • Lee, Seong-Hyeon;Kang, Min-Suk;Park, Sang-Hong;Shin, Seung-Yong;Yang, Eunjung;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.9
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    • pp.930-937
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    • 2014
  • Inverse synthetic aperture radar (ISAR) images can be generated by radar which radiates the electromagnetic wave to a target and receives signal reflected from the target. ISAR images can be widely used to target detection and recognition. This paper proposed a method of generation of high resolution ISAR images by synthesizing frequency spectrums of each stepped chirp waveform in one burst and sub-sampling in frequency domain. This process is performed over entire bursts during coherent processing interval. Conventional ISAR image generation method using stepped frequency waveform has a severe problem of short unambiguous range, loading to ghost phenomenon. However, this problem can be resolved by the proposed method. In simulations, we generate high resolution ISAR image of the moving target which is Boeing-737 aircraft model composed of several ideal point scatterers.

Construction of Static 3D Ultrasonography Image by Radiation Beam Tracking Method from 1D Array Probe (1차원 배열 탐촉자의 방사빔추적기법을 이용한 정적 3차원 초음파진단영상 구성)

  • Kim, Yong Tae;Doh, Il;Ahn, Bongyoung;Kim, Kwang-Youn
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.2
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    • pp.128-133
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    • 2015
  • This paper describes the construction of a static 3D ultrasonography image by tracking the radiation beam position during the handy operation of a 1D array probe to enable point-of-care use. The theoretical model of the transformation from the translational and rotational information of the sensor mounted on the probe to the reference Cartesian coordinate system was given. The signal amplification and serial communication interface module was made using a commercially available sensor. A test phantom was also made using silicone putty in a donut shape. During the movement of the hand-held probe, B-mode movie and sensor signals were recorded. B-mode images were periodically selected from the movie, and the gray levels of the pixels for each image were converted to the gray levels of 3D voxels. 3D and 2D images of arbitrary cross-section of the B-mode type were also constructed from the voxel data, and agreed well with the shape of the test phantom.

Novel Dioxygenases, HIF-α Specific Prolyl-hydroxylase and Asparanginyl-hydroxylase: O2 Switch for Cell Survival

  • Park, Hyun-Sung
    • Toxicological Research
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    • v.24 no.2
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    • pp.101-107
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    • 2008
  • Studies on hypoxia-signaling pathways have revealed novel Fe(II) and $\alpha$-ketoglutarate-dependent dioxygenases that hydroxylate prolyl or asparaginyl residues of a transactivator, Hypoxia-Inducible $Factor-\alpha(HIF-\alpha)$ protein. The recognition of these unprecedented dioxygenases has led to open a new paradigm that the hydroxylation mediates an instant post-translational modification of a protein in response to the changes in cellular concentrations of oxygen, reducing agents, or $\alpha$-ketoglutarate. Activity of $HIF-\alpha$ is repressed by two hydroxylases. One is $HIF-\alpha$ specific prolyl-hydroxylases, referred as prolyl-hydroxylase domain(PHD). The other is $HIF-\alpha$ specific asparaginyl-hydroxylase, referred as factor-inhibiting HIF-1(FIH-1). The facts (i) that many dioxygenases commonly use molecular oxygen and reducing agents during detoxification of xenobiotics, (ii) that detoxification reaction produces radicals and reactive oxygen species, and (iii) that activities of both PHD and FIH-1 are regulated by the changes in the balance between oxygen species and reducing agents, imply the possibility that the activity of $HIF-\alpha$ can be increased during detoxification process. The importance of $HIF-\alpha$ in cancer and ischemic diseases has been emphasized since its target genes mediate various hypoxic responses including angiogenesis, erythropoiesis, glycolysis, pH balance, metastasis, invasion and cell survival. Therefore, activators of PHDs and FIH-1 can be potential anticancer drugs which could reduce the activity of HIF, whereas inhibitors, for preventing ischemic diseases. This review highlights these novel dioxygenases, PHDs and FIH-1 as specific target against not only cancers but also ischemic diseases.

Codon Usage Bias and Determining Forces in Taenia solium Genome

  • Yang, Xing;Ma, Xusheng;Luo, Xuenong;Ling, Houjun;Zhang, Xichen;Cai, Xuepeng
    • Parasites, Hosts and Diseases
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    • v.53 no.6
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    • pp.689-697
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    • 2015
  • The tapeworm Taenia solium is an important human zoonotic parasite that causes great economic loss and also endangers public health. At present, an effective vaccine that will prevent infection and chemotherapy without any side effect remains to be developed. In this study, codon usage patterns in the T. solium genome were examined through 8,484 protein-coding genes. Neutrality analysis showed that T. solium had a narrow GC distribution, and a significant correlation was observed between GC12 and GC3. Examination of an NC (ENC vs GC3s)-plot showed a few genes on or close to the expected curve, but the majority of points with low-ENC (the effective number of codons) values were detected below the expected curve, suggesting that mutational bias plays a major role in shaping codon usage. The Parity Rule 2 plot (PR2) analysis showed that GC and AT were not used proportionally. We also identified 26 optimal codons in the T. solium genome, all of which ended with either a G or C residue. These optimal codons in the T. solium genome are likely consistent with tRNAs that are highly expressed in the cell, suggesting that mutational and translational selection forces are probably driving factors of codon usage bias in the T. solium genome.