• Molecules and Cells
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• v.41 no.5
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• pp.381-389
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• 2018

ARF is a tumor suppressor protein that has a pivotal role in the prevention of cancer development through regulating cell proliferation, senescence, and apoptosis. As a factor that induces senescence, the role of ARF as a tumor suppressor is closely linked to the p53-MDM2 axis, which is a key process that restrains tumor formation. Thus, many cancer cells either lack a functional ARF or p53, which enables them to evade cell oncogenic stress-mediated cycle arrest, senescence, or apoptosis. In particular, the ARF gene is a frequent target of genetic and epigenetic alterations including promoter hyper-methylation or gene deletion. However, as many cancer cells still express ARF, pathways that negatively modulate transcriptional or post-translational regulation of ARF could be potentially important means for cancer cells to induce cellular proliferation. These recent findings of regulators affecting ARF protein stability along with its low levels in numerous human cancers indicate the significance of an ARF post-translational mechanism in cancers. Novel findings of regulators stimulating or suppressing ARF function would provide new therapeutic targets to manage cancer- and senescence-related diseases. In this review, we present the current knowledge on the regulation and alterations of ARF expression in human cancers, and indicate the importance of regulators of ARF as a prognostic marker and in potential therapeutic strategies.

• Journal of Yeungnam Medical Science
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• v.35 no.2
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• pp.141-149
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• 2018

With the enthusiasm regarding robotic application in radical prostatectomy in accordance with the widespread use of serum prostate-specific antigen as a screening test, the number of surgeries performed for complete removal of the gland is increasing continuously. However, owing to the adjacent anatomical location of the prostate to the nerve and urethral sphincter complex, functional recovery, namely improvement from post-prostatectomy incontinence (PPI) and post-prostatectomy erectile dysfunction, still remains a main problem for patients who are reluctant to undergo surgery and tend to choose alternative ways instead. Since the late 1980s, the introduction of radical prostatectomy by open surgical modalities, the depth of the anatomical understanding of the structure surrounding the prostate is getting tremendous, which leads to the development of new surgical modalities and techniques that are consequently aimed at reducing the incidences of PPI and erectile dysfunction. Briefly, recent data from robotic radical prostatectomy, particularly on PPI, are quite acceptable, but by contrast, the reported potency regain rate still remains <20%, which indicates the need for advanced surgical modification to overcome it. In this review, the authors summarized the recent findings on the anatomy and surgical techniques reported up to now.

• BMB Reports
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• v.55 no.7
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• pp.323-335
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• 2022

Together with neuronal loss, the existence of insoluble inclusions of alpha-synuclein (α-syn) in the brain is widely accepted as a hallmark of synucleinopathies including Parkinson's disease (PD), multiple system atrophy, and dementia with Lewy body. Because the α-syn aggregates are deeply involved in the pathogenesis, there have been many attempts to demonstrate the mechanism of the aggregation and its potential causative factors including post-translational modifications (PTMs). Although no concrete conclusions have been made based on the previous study results, growing evidence suggests that modifications such as phosphorylation and ubiquitination can alter α-syn characteristics to have certain effects on the aggregation process in PD; either facilitating or inhibiting fibrillization. In the present work, we reviewed studies showing the significant impacts of PTMs on α-syn aggregation. Furthermore, the PTMs modulating α-syn aggregation-induced cell death have been discussed.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.158-158
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• 1999

The post ion implantation has been applied to modify early-grown BN layer and improve the adhesion of the BN films. The effect of ion implantation doses on microstructure and interlayer was investigated by FTIR and HRTEM. And the hardness and delamination life time of N+-implanted BN films were measured. With increasing the ion dose up to 5.0×1015atoms/㎠, the change of IR spectrum is observed. At 5.0×1016atoms/㎠, a drastic transition of cubic phase into hexagonal phase is detected. The change of microstructure of early-grown layers by ion implantation is confirmed using HRTEM. Both microhardness and delamination life time of BN films increase with ion dose. The modification model of early-grown BN layers is briefly discussed based on the displacement per atom and excess boron in the BN film induced by ion irradiation.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1101-1108
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• 2008

Geldanamycin and its analogs are important anticancer agents that inhibit the newly targeted heat-shock protein (Hsp) 90, which is a chaperone protein in eukaryotic cells. To resolve which geldanamycin biosynthetic genes are responsible for particular post-polyketide synthase (PKS) processing steps and in which order the reactions occur, we individually inactivated candidate genes in Streptomyces hygroscopicus subsp. duamyceticus JCM4427 and isolated and elucidated the structures of intermediates from each mutant. The results indicated that gel7 governs at least one of the benzoquinone ring oxidation steps. The gel16 was found to be involved in double-bond formation between C-4 and C-5 of 4,5-dihydrogeldanamycin, which confirmed our previous findings that this double bond is reduced during the post-PKS modification of the polyketide assembly. In addition, pro-geldanamycin, which does not possess a double bond at C-4/5, was purified from the gel7 and gel8 double-gene-inactivated mutant.

• The Korean Journal of Mycology
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• v.18 no.4
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• pp.209-217
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• 1990

The influence of cellulosic and hemicellulosic substrates on the production of cellulase and xylanase complexes in Aspergillus niger was investigated. The culture conditions with different substrates exhibited profound effects on the level of endoglucanase (CMCase), ${\beta}-glucosidase$, endoxylanase and ${\beta}-xylosidase$, and on their isozyme patterns. However, intracellular and extracellular isozyme patterns of cellulase and xylanase complexes were qualitatively identical and appeared to be simultaneous in the early growth phase. Prolonged incubation led to the increase in the concentrations of isozymes with a little changes in the relative proportions of those isozymes. These results suggest that the biosynthesis of cellulase and xylanase complexes in A. niger is coordinately regulated at the level of induction. Moreover, multiple forms of extracellular cellulase and xylanase complexes seem to be the outcome of specific gene expression and should not be considered solely as the consequence of post-secretional modification of synthesized enzymes.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.556-565
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• 2023

Fast industrial and agricultural expansion result in the production of heavy metal ions (HMIs). These are exceedingly hazardous to both humans and the environment, and the necessity to eliminate them from aqueous systems prompts the development of novel materials. In the present study, a UIO-66 (COOH)₂ metal-organic framework (MOF) containing free carboxylic acid groups was post-synthetically modified with L-glutamic acid via the solid-solid reaction route. Pristine and glutamic acid-treated MOF materials were characterized in detail using several physicochemical techniques. Single-ion batch adsorption studies of Pb(II) and Hg(II) ions were carried out using pristine as well as amino acid-modified MOFs. We further examined parameters that influence removal efficiency, such as the initial concentration and contact time. The bare MOF had a higher ion adsorption capacity for Pb(II) (261.87 mg/g) than for Hg(II) ions (10.54 mg/g) at an initial concentration of 150 ppm. In contrast, an increased Hg(II) ion adsorption capacity was observed for the glutamic acid-modified MOF (80.6 mg/g) as compared to the bare MOF. The Hg(II) ion adsorption capacity increased by almost 87% after modification with glutamic acid. Fitting results of isotherm and kinetic data models indicated that the adsorption of Pb(II) on both pristine and glutamic acid-modified MOFs was due to surface complexation of Pb(II) ions with available -COOH groups (pyromellitic acid). Adsorption of Hg(II) on the glutamic acid-modified MOF was attributed to chelation, in which glutamic acid grafted onto the surface of the MOF formed chelates with Hg(II) ions.

• Macromolecular Research
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• v.17 no.4
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• pp.259-264
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• 2009

Chemical modification of magnetic nanoparticles(MNPs) with functional polymers has recently gained a great deal of attention because of the potential application of MNPs to in vivo and in vitro biotechnology. The potential use of MNPs as capturing agents and sensitive biosensors has been intensively investigated because MNPs exhibit good separation-capability and binding-specificity for biomolecules after suitable surface functionalization processes. In this work, we demonstrate an efficient method for the surface modification of MNPs, by combining surface-initiated polymerization and the subsequent conjugation of the biologically active molecules. The polymeric shells of non-biofouling poly(poly(ethylene glycol) methacrylate)(pPEGMA) were introduced onto the surface of MNPs by surface-initiated, atom transfer radical polymerization(SI-ATRP). With biotin as a model of biologically active compounds, the polymeric shells underwent successful post-functionalization via activation of the polymeric shells and bioconjugation of biotin. The resulting MNP hybrids showed a biospecific binding property for streptavidin and could be separated by magnet capture.

• Journal of Welding and Joining
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• v.25 no.3
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• pp.78-84
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• 2007

Laser Material Processing has been replaced the conventional machining systems - cutting, drilling, welding and surface modification and so on. Especially, LTH(Laser Transformation Hardening) process is one branch of the laser surface modification process. Conventionally, some techniques like a gas carburizing and nitriding as well as induction and torch heating have been used to harden the carbon steels. But these methods not only request post-machining resulted from a deformation but also have complex processing procedures. Besides, LTH process has some merits as : 1. It is easy to control the case depth because of output(laser power) adjustability. 2. It is able to harden the localized and complicated a.ea and minimize a deformation due to a unique property of a localized heat source. 3. An additional cooling medium is not required due to self quenching. 4. A prominent hardening results can be obtained. This study is related to the surface hardening of the rod-shaped carbon steel applied to the lathe based complex processing mechanism, a basic behavior of surface hardening, hardness distribution and structural characteristics in the hardened zone.

• The Research Journal of the Costume Culture
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• v.22 no.6
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• pp.899-910
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• 2014

The purpose of this study was to analyze high school students' school uniform wearing attitude by group according to clothing attitude targeting Gyeongnam area. This study aims to provide preliminary data in the field of school uniform and marketing that clothing propensity by groups is considered. This study conducted a survey targeting 762 high school students in Gyeongnam. For statistical analysis, SPSS for Window 14.0 was used for frequency analysis, factor analysis, reliability analysis, multiple sponse analysis, cluster analysis, ANOVA analysis and Duncan's ex-post analysis method. As a result of cluster analysis on the clothing attitude, students were divided into 4 segmentation of fashion seeking group, fashion indifference group, conformity group and modesty group. As a result of verification on the difference in perception toward wearing school uniform by groups which were classified according to the propensity of clothing attitude, activity, stability, and practicality were all varied according to the propensity of clothing attitude. 4 groups were significant differences in the degree of consent to wearing school uniform, price of school uniforms, tendency to prefer famous brand when purchasing school uniform, experience of transforming school uniform, opinion about school uniform modification and reason for school uniform modification. While low graders were many in 'modesty group', upper graders were many in 'fashion seeking group', which means that more segmentalized satisfaction of clothing by group may be raised if such a fact is considered when planning clothing for high school students segmentalized by age.