• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.1571-1576
• /
• 2016

Alteration of the acetylation status of chromatin and other non-histone proteins by HDAC inhibitors has evolved as an excellent epigenetic strategy in treatment of cancers. The present study was sought to identify compounds with positive pharmacological profiles targeting HDAC1. Analogues of Vorinostat synthesized by Cai et al, 2015 formed the test compounds for the present pharmacological evaluation. Hydroxamte analogue 6H showed superior pharmacological profile in comparison to all the compounds in the analogue dataset owing to its better electrostatic interactions and hydrogen bonding patterns. In order to identify compounds with even better high affinity and pharmacological profile than 6H and Vorinostat, virtual screening was performed. A total of 83 compounds similar to Vorinostat and 154 compounds akin to analogue 6H were retrieved. SCHEMBL15675695 (PubCid: 15739209) and AKOS019005527 (PubCid: 80442147) similar to Vorinostat and 6H, were the best docked compounds among the virtually screened compounds. However, in spite of having good affinity, none of the virtually screened compounds had better affinity than that of 6H. In addition SCHEMBL15675695 was predicted to be a carcinogen while AKOS019005527 is Ames toxic. From, our extensive analysis involving binding affinity analysis, ADMET properties predictions and pharmacophoric mappings, we report Vorinostat hydroxamate analogue 6H to be a potential candidate for HDAC inhibition in treatment of cancers through an epigenetic strategy.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.1
• /
• pp.52-58
• /
• 2014

Structurally, herboxidiene contains the tetrahydropyran acetic acid moiety and a side chain including a conjugated diene, and has been isolated from Streptomyces chromofuscus ATCC 49982. Its production was significantly elevated nearly 13.5-fold (0.74 g/l) in a medium supplemented with glycerol (medium No. 6A6), and was more efficacious (1.08 g/l; 19.8-fold) in fed-batch fermentation at 36 h in medium No. 6A6, from Streptomyces chromofuscus. For further enhancement, regulatory genes metK1-sp and afsR-sp from Streptomyces peucetius were overexpressed using an expression vector, pIBR25, and similarly ACCase from Streptomyces coelicolor and two genes, metK1-sp and afsR-sp, were also overexpressed using an integration vector, pSET152, under the control of the strong $ermE^*$ promoter in Streptomyces chromofuscus. Only the recombinant strains S. chromofuscus SIBR, S. chromofuscus GIBR, and S. chromofuscus AFS produced more herboxidiene than the parental strain in optimized medium No. 6A6 with an increment of 1.32-fold (0.976 g/l), 3.85-fold (2.849 g/l), and 1.7-fold(1.258 g/l) respectively.

• Journal of the Korean Chemical Society
• /
• v.14 no.3
• /
• pp.207-212
• /
• 1970

A large variety of weed killers, insecticides, and bactericiedes on the market today are of almost infinite variety, but their pharmacological effects are different from each other according to the objects to cope with. Therefore, it is hoped that some chemical substance which serves as weed killer, an insecticide, and a bactericede at a same time, should be synthesized, in order to save expense and labor. I anticipated that the desire would be met by introducing to a molecule the radical which has the three effects. Here, I made an attempt of introducing $Cl_2$ gas to aniline considering the following respects: 1. Introduction velocity of $Cl_2$ gas under the varied temeratures and velocities of $Cl_2$ gas 2. The effect of reaction period under the condition which gives the most satisfactory yield. 3. The actions of catalysts, $SbCl_3$, $FeCl_3$, and $MoCl_5$, and their proportions when a mixture of the three catalysts is used in producing 2,6-dichloro-aniline. After consideration of above phenomena, the maximum production rate of 79.5% of 2.6-compound was obtained. With the compound I synthesized 2.6-dichloro-4-nitroaniline-mercuric acetate. Investigations of the effects of the compound as weed killer, an insecticide, and a bactericide showed that the compound, 2,6-dichloro-4-Nitro Aniline mercuric acetate has a satisfactory herbi-insecti-bactericidal effect.

• International Journal of Oral Biology
• /
• v.38 no.2
• /
• pp.73-80
• /
• 2013

Leptin is one of the adipocytokines produced from adipose tissue but its functions in periodontal tissue have not previously been investigated. In our current study, we examined the effects of leptin on the expression of interleukin (IL)-6 and IL-8 in periodontal ligament (PDL) cells and gingival fibroblasts. Leptin receptor expression was evaluated by RT-PCR and the production of cytokines was measured by ELISA. The phosphorylation of Akt and Erk1/2 was assessed by western blotting. mRNA of long and short form leptin receptors were detected in both PDL cells and gingival fibroblasts. Leptin was found to increase the production of IL-6 and IL-8 in both of these cell types, an effect which was not blocked by polymyxin B, an inhibitor of lipopolysaccharide (LPS). Leptin did not alter the production of IL-6 and IL-8 induced by LPS in PDL cells but increased Akt and Erk1/2 phosphorylation in these cells. These results suggest that leptin acts as an inducer of IL-6 and IL-8 in PDL cells and gingival fibroblasts.

• Current Optics and Photonics
• /
• v.2 no.6
• /
• pp.582-588
• /
• 2018

A $Nd:YVO_4$ laser dual-end-pumped by a wavelength-locked 878.6 nm laser diode is presented. At the repetition rate of 500 KHz, the absorbed pump power of 58 W, an output power of 26.1 W at 1064 nm is obtained, corresponding to an optical-optical efficiency of 45%. The pulse width is 44.2 ns. Meanwhile, the effects of traditional 808 nm pumping and 878.6 nm dual-end-pumping on the output laser beam quality and pulse width are compared and analyzed in an experiment.

• Journal of Internet Computing and Services
• /
• v.8 no.4
• /
• pp.81-91
• /
• 2007

Binding update for the routing optimization in MIPv6 can make the involved nodes vulnerable to various attacks. Therefore, secure binding update becomes an important research issue in MIPv6, and several protocols have been proposed for this purpose. In this paper, we compare several existing binding update protocols such as RR, SUCV and OMIPv6 and analyze the vulnerability of nodes to the possible attacks and drawbacks of address management and scalability and overhead of encryption operations. Then, we suggest the design requirements for the secure binding update and propose an advanced protocol based on the design principle. Through the analysis, we show that our protocol can achieve a higher level of security against the various attacks and enable better management of address, provide the location privacy and reduce the computational overhead of mobile nodes with constraint computational power.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.7 no.1
• /
• pp.75-83
• /
• 2008

In this paper, we propose an efficient algorithm that assigns single temporary IPv4 address and port number to improve efficiency of IPv4 address that is allocated in DSTM service. And, we have analyzed the elementary functions for DSTM and have designed the functional modules. Also, we have implemented the DTI interface for encapsulation and decapsulation of IPv6 packets. The performance analysis and comparison are investigated whether the appropriate interworking service is possible or not. Our observation results show that the performance of IPv4 over IPv6 tunneling is suitable to DSTM service due to the reduction of delay by eliminating checksum calculations in the header of IPv6 tunneling.

• Journal of Sensor Science and Technology
• /
• v.27 no.6
• /
• pp.374-379
• /
• 2018

The piezocomposite transducer is widely used because it is highly efficient in transforming electric energy into mechanical energy, and its frequency range is broader than that of other types of ultrasound transducers. A general piezocomposite transducer is composed of an acoustic lens, impedance matching layers, piezoelectric materials, and backing layers. When an input voltage is applied to a piezoelectric material as an active material, it generates sound waves while vibrating. At that time, an impedance matching layer helps the sound waves to propagate forward while reducing the impedance mismatch that may occur at the interface between the active material and its front material. The impedance mismatch has a negative effect on the signal of an ultrasound transducer; thus, it is important to design a matching layer to overcome the issue. In this study, an optimized feature of a matching layer with gradient properties is studied. An objective function is defined to minimize both the average and the deviation of the reflection coefficients that are functions of the frequencies. As a result, an improvement in the signal characteristics with respect to the sensitivity and bandwidth is reported.

• 한국ITS학회:학술대회논문집
• /
• 2004.11a
• /
• pp.115-119
• /
• 2004

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1269-1276
• /
• 2011

In the Proxy Mobile IPv6 (PMIPv6), the data transmission performance may be degraded when the two communicating hosts are located within the same mobile domain, since all the data packet shall be delivered by way of Local Mobility Anchor (LMA). In this paper we propose an extensional scheme of PMIPv6 using binding query. In the proposed Query-based PMIPv6 (Q-PMIPv6) scheme, the Mobile Access Gateway (NAG) of Correspondent Node (CN) sends a binding query to LMA to obtain the Proxy Care-of-Address of Mobile Node (MN). Since then, CN and MN can communicate with each other by using an optimized data path. For comparison, we performed the numerical analysis and the ns-2 simulations for the proposed Q-PMIPv6 scheme and the existing PMIPv6 and PMIPv6 Localized Routing (PMIPv6-LR). From the results, we can see that the proposed scheme outperforms the existing PMIPv6 and PMIPv6-LR schemes in terms of the signaling control and data delivery costs.