• Title/Summary/Keyword: associated 1-forms

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The Characteristices of Step Responses of the Manabe Standard Forms and Its Application to the Controller Desegn (Manabe 표준형의 계단 응답 특성 및 제어기설계에의 응용)

  • Gang, Hwan-Il
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.5
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    • pp.586-592
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    • 1999
  • We investigate the characteristic of 소데 responses of the Manabe standard form which is used recently for design of the controller. We obtain some theorems and these theorems have the properties of the relationship between the roots of the polynomial and the stability indices which are used for the Manabe standard form. The Manabe standard form has the following properties: The sum of the squal to zero, the sum of the reciprocal of the squared roots is greater than zero and the parameter $\tau$ is the negative value of the sum of the reciprocal of the roots. We compare the step responses of the Manabe standard form with those of the ITAE form, the dead beat response and Bessel forms. We choose the 6th order closed loop polynomial and keep the same settling time for the four forms. Under these conditions we find that the Manabe standard form have faster 90% rising time than the Bessel and dead beat response. We see that the ITAE, bessel and dead beat responses have some overshoot, whereas the Manabe standard form has none. We also compare the Manabe form with the other three forms for the controller design using the pole assignment technique. If the open loop transfer function is a type-1 system (transfer functions having one integrator), then, for the closed loop system associated with the open loop transfer function, the steady state error of the unit ramp input is obtained in terms of the parameter $\tau$ of the Manabe standard form.

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Analysis of Gene Expression in 4,4'-Methylenedianiline-induced Acute Hepatotoxicity

  • Oh, Jung-Hwa;Yoon, Hea-Jin;Lim, Jung-Sun;Park, Han-Jin;Cho, Jae-Woo;Kwon, Myung-Sang;Yoon, Seok-Joo
    • Toxicological Research
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    • v.25 no.2
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    • pp.85-92
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    • 2009
  • 4,4'-Methylenedianiline (MDA) is an aromatic amine that is widely used in the industrial synthetic process. Genotoxic MDA forms DNA adducts in the liver and is known to induce liver damage in human and rats. To elucidate the molecular mechanisms associated with MDA-induced hepatotoxicity, we have identified genes differentially expressed by microarray approach. BALB/c male mice were treated once daily with MDA (20 mg/kg) up to 7 days via intraperitoneal injection (i.p.) and hepatic damages were revealed by histopathological observation and elevation of serum marker enzymes such as AST, ALT, ALP, cholesterol, DBIL, and TBIL. Microarray analysis showed that 952 genes were differentially expressed in the liver of MDA-treated mice and their biological functions and canonical pathways were further analyzed using Ingenuity Pathways Analysis (IPA). Toxicological functional analysis showed that genes related to hepatotoxicity such hyperplasia/hyperproliferation (Timp1), necrosis/cell death (Cd14, Mt1f, Timp1, and Pmaip1), hemorrhaging (Mt1f), cholestasis (Akr1c3, Hpx, and Slc10a2), and inflammation (Cd14 and Hpx) were differentially expressed in MDA-treated group. This gene expression profiling should be useful for elucidating the genetic events associated with aromatic amine-induced hepatotoxicity and for discovering the potential biomarkers for hepatotoxicity.

Peripheral Neuropathy Associated with Human Immunodeficiency Virus Infection (사람면역결핍바이러스 감염과 연관된 말초신경병증)

  • Lee, Min Hwan;Lim, Young-Min;Pyun, So Young;Kim, Jimin;Kim, Kwang-Kuk
    • Annals of Clinical Neurophysiology
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    • v.14 no.1
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    • pp.29-35
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    • 2012
  • Background: Peripheral neuropathy is the most frequent neurological complication in human immunodeficiency virus (HIV) infection, related with diverse etiologies including inflammation, opportunistic infection and side effects of medications. The purpose of the present study was to evaluate characteristics of HIV associated neuropathy according to the stage of HIV infection. Methods: In reviewing the medical records of HIV patients who underwent electrodiagnostic studies between 1997 and 2011, total 11 patients (all males; median age, 47 years; range, 28-71 years) with comorbid neuropathy were enrolled. Stage of HIV infection was categorized according to the Centers for Disease Control and Prevention (CDC) criteria. Classification of peripheral neuropathy was based on clinical and electrophysiological features. Results: Distal symmetric polyneuropathy was observed in 8 patients (72.7%), inflammatory demyelinating polyneuropathy in 2 patients (18.1%), and polyradiculopathy in 1 patient (9.1%). Median CD4+ T cell count was $123/mm^3$ (range, $8-540/mm^3$) and 7 patients (60%) had the most advanced HIV disease stage (CDC-C3). There was no neuropathy caused by CMV infection. Conclusions: Distal symmetric polyneuropathy was the most common type of neuropathy in HIV infection, but various forms of neuropathy such as inflammatory demyelinating polyneuropathy and polyradiculopathy were also present. HIV associated neuropathy is more frequently associated with advancing immunosuppression, although it can occur in all stages of HIV infection.

A Novel Role of Hyaluronic Acid and Proteoglycan Link Protein 1 (HAPLN1) in Delaying Vascular Endothelial Cell Senescence

  • Dan Zhou;Ji Min Jang;Goowon Yang;Hae Chan Ha;Zhicheng Fu;Dae Kyong Kim
    • Biomolecules & Therapeutics
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    • v.31 no.6
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    • pp.629-639
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    • 2023
  • Cardiovascular diseases (CVDs) are the most common cardiovascular system disorders. Cellular senescence is a key mechanism associated with dysfunction of aged vascular endothelium. Hyaluronic acid and proteoglycan link protein 1 (HAPLN1) has been known to non-covalently link hyaluronic acid (HA) and proteoglycans (PGs), and forms and stabilizes HAPLN1-containing aggregates as a major component of extracellular matrix. Our previous study showed that serum levels of HAPLN1 decrease with aging. Here, we found that the HAPLN1 gene expression was reduced in senescent human umbilical vein endothelial cells (HUVECs). Moreover, a recombinant human HAPLN1 (rhHAPLN1) decreased the activity of senescence-associated β-gal and inhibited the production of senescence-associated secretory phenotypes, including IL-1β, CCL2, and IL-6. rhHAPLN1 also downregulated IL-17A levels, which is known to play a key role in vascular endothelial senescence. In addition, rhHAPLN1 protected senescent HUVECs from oxidative stress by reducing cellular reactive oxygen species levels, thus promoting the function and survival of HUVECs and leading to cellular proliferation, migration, and angiogenesis. We also found that rhHAPLN1 not only increases the sirtuin 1 (SIRT1) levels, but also reduces the cellular senescence markers levels, such as p53, p21, and p16. Taken together, our data indicate that rhHAPLN1 delays or inhibits the endothelial senescence induced by various aging factors, such as replicative, IL-17A, and oxidative stress-induced senescence, thus suggesting that rhHAPLN1 may be a promising therapeutic for CVD and atherosclerosis.

Genetic factors associated with development of cerebral malaria and fibrotic schistosomiasis

  • Hirayama, Kenji
    • Parasites, Hosts and Diseases
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    • v.40 no.4
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    • pp.165-172
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    • 2002
  • Collaborative studies have identified some genetic factors contributing to the development of severe forms of malaria and schistosomiasis. In Thailand, the $TNF-{\alpha}{\;}5'-flanking$ region shows biallelic polymorphic sites at nucleotides -238, -308, -857, -863, and -1031, and seven alleles have been identified in patients from Myanmar. We found that the TNF promoter (TNFP)-D allele was significantly associated with cerebral malaria in populations from Karen (P < 0.0001. OR = 124.86) and ethnic Burma (P < 0.0001, OR = 34.50) . In China, we have identified two major genes related to the severity of liver fibrosis, one an HLA class II gene, and the other the IL-13 gene. The frequency of the HLA- DRB5*0101 allele and that of the IL-13 promoter A/A (IL- l3P- A/A) genotype were elevated in fibrotic patients, although the two genes are located on different chromosomes, chromosomes 6p and 5q, respectively Subjects with both genotypes had odds ratios (OR = 24.5) much higher than the sum of the ratios for each individual genotype (OR = 5.1,95% Confidence Interval 1.3-24.7 for HLA-DRB5*0101, OR = 3.1 95% CI 1.5 - 6.5 for IL-l3P-A/A). That the effects of the two susceptibility markers are synergistic rather than additive, strongly suggests that the pathogenic Th2 response directly influences the prognosis of post-schistosomal liver fibrosis.

FOOTPRINT AND MINIMUM DISTANCE FUNCTIONS

  • Nunez-Betancourt, Luis;Pitones, Yuriko;Villarreal, Rafael H.
    • Communications of the Korean Mathematical Society
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    • v.33 no.1
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    • pp.85-101
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    • 2018
  • Let S be a polynomial ring over a field K, with a monomial order ${\prec}$, and let I be an unmixed graded ideal of S. In this paper we study two functions associated to I: The minimum distance function ${\delta}_I$ and the footprint function $fp_I$. It is shown that ${\delta}_I$ is positive and that $fp_I$ is positive if the initial ideal of I is unmixed. Then we show that if I is radical and its associated primes are generated by linear forms, then ${\delta}_I$ is strictly decreasing until it reaches the asymptotic value 1. If I is the edge ideal of a Cohen-Macaulay bipartite graph, we show that ${\delta}_I(d)=1$ for d greater than or equal to the regularity of S/I. For a graded ideal of dimension ${\geq}1$, whose initial ideal is a complete intersection, we give an exact sharp lower bound for the corresponding minimum distance function.

Lichen-Associated Bacterium, a Novel Bioresource of Polyhydroxyalkanoate (PHA) Production and Simultaneous Degradation of Naphthalene and Anthracene

  • Nahar, Shamsun;Jeong, Min-Hye;Hur, Jae-Seoun
    • Journal of Microbiology and Biotechnology
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    • v.29 no.1
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    • pp.79-90
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    • 2019
  • Lichens are generally known as self-sufficient, symbiotic life-forms between fungi and algae/cyanobacteria, and they also provide shelter for a wide range of beneficial bacteria. Currently, bacterial-derived biodegradable polyhydroxyalkanoate (PHA) is grabbing the attention of many researchers as a promising alternative to non-degradable plastics. This study was conducted to develop a new method of PHA production using unexplored lichen-associated bacteria, which can simultaneously degrade two ubiquitous industrial toxins, anthracene and naphthalene. Here, 49 lichen-associated bacteria were isolated and tested for PHA synthesis. During the GC-MS analysis, a potential strain of EL19 was found to be a 3-hydroxyhexanoate (3-HHx) accumulator and identified as Pseudomonas sp. based on the 16S rRNA sequencing. GC analysis revealed that EL19 was capable of accumulating 30.62% and 19.63% of 3-HHx from naphthalene and anthracene, respectively, resulting in significant degradation of 98% and 96% of naphthalene and anthracene, respectively, within seven days. Moreover, the highly expressed phaC gene verified the genetic basis of $PHA_{mcl}$ production under nitrogen starvation conditions. Thus, this study strongly supports the hypothesis that lichen-associated bacteria can detoxify naphthalene and anthracene, store energy for extreme conditions, and probably help the associated lichen to live in extreme conditions. So far, this is the first investigation of lichen-associated bacteria that might utilize harmful toxins as feasible supplements and convert anthracene and naphthalene into eco-friendly 3-HHx. Implementation of the developed method would reduce the production cost of $PHA_{mcl}$ while removing harmful waste products from the environment.

Heme Oxygenase-1 : Its Therapeutic Roles in Inflammatory Diseases

  • Pae, Hyun-Ock;Chung, Hun-Taeg
    • IMMUNE NETWORK
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    • v.9 no.1
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    • pp.12-19
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    • 2009
  • Heme oxygenase (HO)-1 is an inducible enzyme that catalyzes the first and rate-limiting step in the oxidative degradation of free heme into ferrous iron, carbon monoxide (CO), and biliverdin (BV), the latter being subsequently converted into bilirubin (BR). HO-1, once expressed during inflammation, forms high concentrations of its enzymatic by-products that can influence various biological events, and this expression is proven to be associated with the resolution of inflammation. The degradation of heme by HO-1 itself, the signaling actions of CO, the antioxidant properties of BV/BR, and the sequestration of ferrous iron by ferritin all concertedly contribute to the anti-inflammatory effects of HO-1. This review focuses on the anti-inflammatory mechanisms of HO-1 actions and its roles in inflammatory diseases.

Is Exposure to Tobacco Advertising, Promotion and Sponsorship Associated with Initiation of Tobacco Use among Current Tobacco Users in Youth in India?

  • Sardana, Mohini;Goel, Sonu;Gupta, Madhu;Sardana, Veera;Singh, BS
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6299-6302
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    • 2015
  • Background: The rise in consumption of tobacco products among youth is a public health concern in India. Several studies have shown that advertisements promoting tobacco products influence decisions and behaviour of youth towards smoking. Objective: To ascertain which method of Tobacco Advertising, Promotion and Sponsorship (TAPS) was more influential for initiating tobacco use in youth in India. Materials and Methods: The secondary data of youth (15-24 years) from nationally representative Global Adult Tobacco Survey (GATS) conducted in 2009-2010 was analyzed. Odds ratio and p-value were used to know the association between TAPS and initiation of use of tobacco products among youth. Logistic regression was used to determine the most significant means of TAPS altering the youth's behaviour towards tobacco products. Results: Out of 13,383 youths, 1,982 (14.7%) used smokeless forms of tobacco and 860 (6.38%) used smoke forms. Logistic regression reveals that promotional activities mainly through cinemas (p<0.05) and providing free samples of tobacco products (p < = .001) were most influential means of initiating consumption of tobacco products among youth. Conclusions: The smoking in youth is associated with watching advertisements particularly in cinema and promotional activities like distribution of free samples, coupons and sales on the price of tobacco products. Stronger legislative measures should be enforced to curb promotional advertisements in cinemas and distribution of free samples.

The C-terminal Region of Human Tau Protein with Ability of Filament Formation

  • Chung, Sang-Ho
    • Animal cells and systems
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    • v.1 no.2
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    • pp.317-321
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    • 1997
  • Tau protein is one of the microtubule-associated proteins in the mammalian brain. In Alzheimer's disease, tau protein is immobilized in the somatodendritic compartment of certain nerve cells, where it forms a part of the paired helical filament (PHF). To understand the role of tau protein in the formation of PHF, a recombinant human tau protein expressed in Escherichia coli and five synthetic peptide fragments (peptide 1 to peptide 5), corresponding to the C-terminal region of tau protein, were prepared and their ability in self-assembly to form filamentous structures was examined. The recombinant human tau protein formed short rod-like structures in 0.1M MES buffer containing 1 mM $MgCI_2$, while a synthetic peptide fragment 1 containing 55 amino acid residues could assemble into a lot of long filamentous structures in water and particularly twisted helical structures in 0.1M MES buffer containing 1 mM $MgCI_2$. This suggests that the C-terminal region possesses a filament-forming ability and may be related to the formation of the helical structure by providing a powerful filament-forming driving force.

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