• Journal of Microbiology
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• v.39 no.2
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• pp.109-115
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• 2001

Salmonella typhimurium possesses a cad operon, which contributes to an adaptive response against an acidifying environment. In Escherichia coli, the activation of the cad operon is dependent on cadC, which is located upstream of the operon. However, the activator of cad operon in S. typhimurium has not been known until now. In this study, we selected a putative cadC mutant by trasposon mutagenesis and cloned the cadc of S. typhimurium. Moreover, the cadC mutant was complemented by cadC clone. The cadC gene from S. typhimurium LT-2 consists of 1539 bp encoding a polypeptide ob 512 amino acids, and shows sequence similarity to cadC of E. coli with 53% identity and 67% similarity. The hydrophobicity profile of th S. typhimurim CadC sequence is very similar to E. coli CadC.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.259-264
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• 2001

It has been well known that the expression of S. typhimurium cadBA operon requires at least two extracellular signals: low pH and high concentration of lysine. To better understand the nature of pH-dependent and lysine dependent signal transduction, mutants were isolated in JF2238(cadA-lacZ) by Tn10 insertion, spontaneous mutagenesis, and EMS treatment. Two mutants were isolated from JF2238, expressed as a cadA-lacZ operon fusion in various growth conditions, and analyzed to have mutations in cadC, a gene encoding a function necessary for transcriptional activation of cadBA. One isolate (cadC6) conferred pH-independent and lysine-independent cadBA expression and the other(cadC4) showed pH-independent and lysine-dependent cadBA expression. cadR::Tn10 and cadR4 mutants were expressed in the absence of exogenously added lysine. They were also resistant to thiosine and complemented by lysP clone from E. coli. Thus, in the absence of exogenous lysine, cadR is a negative regulator of cadBA expression. Cadaverine, the product of lysine decarboxylation, was shown to inhibit expression of cadA-lacZ fusion in cad $C^+$ cell.

• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1755-1761
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• 2008

The present study revealed that Lrp, a leucine-responsive regulatory protein, is involved in the regulation of cadBA transcription through activation of $P_{cadBA}$. The influence of Lrp on $P_{cadBA}$ was mediated by CadC, and thereby, CadC was able to compensate for the lack of Lrp in the activation of $P_{cadBA}$. Western blot analyses and EMSA demonstrated that the cellular level of CadC was not significantly affected by Lrp, and that Lrp exerted its effect by directly binding to $P_{cadBA}$. These combined results suggested that CadC and Lrp function cooperatively to activate the $P_{cadBA}$ rather than sequentially in a regulatory cascade.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.1093-1098
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• 2004

An open reading frame encoding CadC, consisting of 526 amino acids, was identified from the upstream region of the Vibrio vulnificus cadBA operon. The deduced amino acid sequences of the cadC were 22 to 78% similar to those reported from other Enterobacteriaceae. Functions of cadC gene on acid tolerance were assessed by comparing acid tolerances of V. vulnificus and its isogenic mutant, whose cadC gene was inactivated by allelic exchanges. The results demonstrated that the gene product of cadC contributes to acid tolerance of V. vulnificus, and that its contribution is dependent on prior exposure of cells to moderately acidic pH. The cellular level of cadB and cadA transcripts decreased in the cadC mutant, indicating that CadC exerts its effect on acid tolerance of V. vulnificus by enhancing the expression of cadBA in a pH-dependent manner.

• Journal of Welding and Joining
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• v.9 no.3
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• pp.52-61
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• 1991

In the recent years the computer-numerical controlled cutting process such as a plasma arc cutting and a laser cutting is widely applied to reduce the time and cost expense for generating NC part program of the parts to be cut. In the present study, a CAD system(C-CAD) was developed to generate automatically the NC part programs with CLDAT(Cutter Location Data)for the CNC plasma arc cutting system. The NC part programs are composed of the 2-dimensional drawing of the parts to be cut and the technological data. The shape data of the parts drawn in the Auto-CAD can be also used in the C-CAD, since the data file generated by the C-CAD is compatible with that by the Auto-CAD. In order to check its applicability, the C-CAD and CAM system were applied to cut the parts, and which showed the satisfactory results.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.289-296
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• 2017

Lysine decarboxylase (CadA) converts ${\small{L}}-lysine$ into cadaverine (1,5-pentanediamine), which is an important platform chemical with many industrial applications. Although there have been many efforts to produce cadaverine through the soluble CadA enzyme or Escherichia coli whole cells overexpressing the CadA enzyme, there have been few reports concerning the immobilization of the CadA enzyme. Here, we have prepared a cross-linked enzyme aggregate (CLEA) of E. coli CadA and performed bioconversion using $CadA^{CLEA}$. $CadA^{free}$ and $CadA^{CLEA}$ were characterized for their enzymatic properties. The optimum temperatures of $CadA^{free}$ and $CadA^{CLEA}$ were $60^{\circ}C$ and $55^{\circ}C$, respectively. The thermostability of $CadA^{CLEA}$ was significantly higher than that of $CadA^{free}$. The optimum pH of both enzymes was 6.0. $CadA^{free}$ could not be recovered after use, whereas $CadA^{CLEA}$ was rapidly recovered and the residual activity was 53% after the $10^{th}$ recycle. These results demonstrate that $CadA^{CLEA}$ can be used as a potential catalyst for efficient production of cadaverine.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.290-295
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• 1989

This paper proposes a Expert CAPP System for integrating CAD/CAM of rotational work-part by rule based approach. The CAD/CAPP integration is performed by the recognition of machined features from the 2-D CAD data (IGES) file. Selecting functions of the process planning are performed in modularized rule base by forward chaining inference, and operation sequences are determined by means of heuristic search algorithm. For CAPP/CAM integration, post-processor generates NC code from route sheet file. This system coded in OPS5 and C language on PC/AT, and EMCO CNC lathe interfaced with PC through DNC and RS-232C.

• BMB Reports
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• v.36 no.2
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• pp.237-242
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• 2003

Hepatic lipase is a key enzyme that is involved in HDL-C metabolism. The goal of this study was to find out the frequency of the hepatic lipase C514T polymorphism, and evaluate its relationship with plasma HDL-C levels and coronary artery disease (CAD) in Koreans. Two hundred and twenty four subjects with no previous history of lipid-lowering therapy, 118 patients with significant CAD, and 106 controls were examined with respect to their genotypes, lipid profiles, and other risk factors for CAD. The frequency of the -514T allele was 0.37 in men and 0.35 in women, which were higher than the frequency that was reported in Caucasians, but lower than the frequency that was reported in African-Americans. The -514T allele was associated with significantly higher HDL-C levels in women. After controlling for age, gender, BMI, DM, and smoking, the non-CC genotype was significantly associated with HDL-C levels, and explained 6% of the HDL-C variation in this study. When the genotypes-distribution was compared between the CAD and non-CAD patients, the hepatic lipase C-514T polymorphism was not associated with the presence of CAD. Koreans have a higher frequency of the hepatic lipase gene 514T allele than Caucasians, and the -514T allele is associated with higher plasma HDL-C levels in Korean women, and perhaps non-smoking men. However, our data does not suggest an association between the polymorphism and an increased risk of CAD.

• Transactions of the KSME C: Technology and Education
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• v.2 no.2
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• pp.125-130
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• 2014

Although the subject of Mechanical Drawing is very important in mechanical engineering education, it is hard to teach the subject effectively, because it needs to carry out lectures and labs in parallel and needs substantially large portion of CAD lab time. In the department of Mechanical Systems and Design Engineering of SNUST, Project Based Learning is adopted to teach the subject of Mechanical Drawing. In this course, students experience to read and to draw drawings through the PBL project after the lectures on mechanical drawings. In this way, they can learn by heart the drawing skills and the operation of CAD software tools. In this paper, various PBL projects and teaching methods carried out in recent years are presented and the effects of the projects are discussed.

• The Journal of Advanced Prosthodontics
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• v.11 no.2
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• pp.95-104
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• 2019

PURPOSE. To evaluate the effect of surface treatments and repair materials on the shear bond strength and to measure the fracture toughness of CAD/CAM provisional restoration materials. MATERIALS AND METHODS. Four CAD/CAM (3D printing: Nextdent C&B and ZMD-1000B Temporary, CAD/CAM resin block: Yamahachi PMMA disk and Huge PMMA block) and four conventional (monometacrylate: Jet and Alike, dimetacrylate: Luxatemp and Protemp 4) materials were selected to fabricate disk-shaped specimens and divided into six groups according to surface treatment (n=10). CAD/CAM materials were repaired with Jet or Luxatemp, while conventional materials were repaired with their own materials. The shear bond strength was measured by using universal testing machine. Ten rectangular column-shaped specimens for each material were fabricated to measure the fracture toughness by single edge v notched beam technique. Statistical analysis was performed by one-way ANOVA. RESULTS. The highest shear bond strength of CAD/CAM materials was achieved by SiC paper + sandblasting. It was also accomplished when repairing 3D printing materials with Luxatemp, and repairing CAD/CAM resin blocks with Jet. Yamahachi PMMA disk showed the highest fracture toughness. Nextdent C&B showed the lowest fracture toughness value but no statistically significant difference from Alike and Luxatemp (P>.05). CONCLUSION. In order to successfully repair the CAD/CAM provisional restoration, mechanical surface treatment and appropriate repair material according to the CAD/CAM material type should be selected. The CAD/CAM provisional materials have proper mechanical properties for clinical use as compared to conventional materials.