• 제목/요약/키워드: $pK_a$

검색결과 82,287건 처리시간 0.098초

miR-30a Regulates the Expression of CAGE and p53 and Regulates the Response to Anti-Cancer Drugs

  • Park, Deokbum;Kim, Hyuna;Kim, Youngmi;Jeoung, Dooil
    • Molecules and Cells
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    • 제39권4호
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    • pp.299-309
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    • 2016
  • We have previously reported the role of miR-217 in anti-cancer drug-resistance. miRNA array and miRNA hybridization analysis predicted miR-30a-3p as a target of miR-217. miR-30a-3p and miR-217 formed a negative feedback loop and regulated the expression of each other. Ago1 immunoprecipitation and co-localization analysis revealed a possible interaction between miR-30a-3p and miR-217. miR-30a-3p conferred resistance to anti-cancer drugs and enhanced the invasion, migration, angiogenic, tumorigenic, and metastatic potential of cancer cells in CAGE-dependent manner. CAGE increased the expression of miR-30a-3p by binding to the promoter sequences of miR-30a-3p, suggesting a positive feedback loop between CAGE and miR-30a-3p. miR-30a-3p decreased the expression of p53, which showed the binding to the promoter sequences of miR-30a-3p and CAGE in anti-cancer drug-sensitive cancer cells. Luciferase activity assays showed that p53 serves as a target of miR-30a. Thus, the miR-30a-3p-CAGE-p53 feedback loop serves as a target for overcoming resistance to anti-cancer drugs.

Association of a p53 Codon 72 Gene Polymorphism with Environmental Factors and Risk of Lung Cancer: a Case Control Study in Mizoram and Manipur, a High Incidence Region in North East India

  • Saikia, Bhaskar Jyoti;Das, Mandakini;Sharma, Santanu Kumar;Sekhon, Gaganpreet Singh;Zomawia, Eric;Singh, Yanglem Mohen;Mahanta, Jagadish;Phukan, Rup Kumar
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권24호
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    • pp.10653-10658
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    • 2015
  • Background: A very high incidence of lung cancer is observed in Mizoram and Manipur, North East India. We conducted a population based case control study to establish associations of p53 codon 72 polymorphisms and interactions with environmental factors for this high incidence. Material and Methods: A total of 272 lung cancer cases and 544 controls matched for age (${\pm}5years$), sex and ethnicity were collected and p53 codon 72 polymorphism genotypes were analyzed using a polymerase chain based restriction fragment length polymorphism assay. We used conditional multiple logistic regression analysis to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors. Results: p53 Pro/Pro genotype was significantly associated with increased risk of lung cancer in the study population (adjusted OR=2.14, CI=1.35-3.38, p=0.001). Interactions of the p53 Pro/Pro genotype with exposure to wood smoke (adjusted OR=3.60, CI=1.85-6.98, p<0.001) and cooking oil fumes (adjusted OR=3.27, CI=1.55-6.87, p=0.002), betel quid chewing (adjusted OR=3.85, CI=1.96-7.55, p<0.001), tobacco smoking (adjusted OR=4.42, CI=2.27-8.63, p<0.001) and alcohol consumption (adjusted OR=3.31, CI=1.10-10.03, p=0.034) were significant regarding the increased risk of lung cancer in the study population. Conclusions: The present study provided preliminary evidence that a p53 codon 72 polymorphism may effect lung cancer risk in the study population, interacting synergistically with environmental factors.

Low Non-NMDA Receptor Current Density as Possible Protection Mechanism from Neurotoxicity of Circulating Glutamate on Subfornical Organ Neurons in Rats

  • Chong, Wonee;Kim, Seong Nam;Han, Seong Kyu;Lee, So Yeong;Ryu, Pan Dong
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권2호
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    • pp.177-181
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    • 2015
  • The subfornical organ (SFO) is one of circumventricular organs characterized by the lack of a normal blood brain barrier. The SFO neurons are exposed to circulating glutamate ($60{\sim}100{\mu}M$), which may cause excitotoxicity in the central nervous system. However, it remains unclear how SFO neurons are protected from excitotoxicity caused by circulating glutamate. In this study, we compared the glutamate-induced whole cell currents in SFO neurons to those in hippocampal CA1 neurons using the patch clamp technique in brain slice. Glutamate ($100{\mu}M$) induced an inward current in both SFO and hippocampal CA1 neurons. The density of glutamate-induced current in SFO neurons was significantly smaller than that in hippocampal CA1 neurons (0.55 vs. 2.07 pA/pF, p<0.05). To further identify the subtype of the glutamate receptors involved, the whole cell currents induced by selective agonists were then compared. The current densities induced by AMPA (0.45 pA/pF) and kainate (0.83 pA/pF), non-NMDA glutamate receptor agonists in SFO neurons were also smaller than those in hippocampal CA1 neurons (2.44 pA/pF for AMPA, p<0.05; 2.34 pA/pF for kainate, p< 0.05). However, the current density by NMDA in SFO neurons was not significantly different from that of hippocampal CA1 neurons (1.58 vs. 1.47 pA/pF, p>0.05). These results demonstrate that glutamate-mediated action through non-NMDA glutamate receptors in SFO neurons is smaller than that of hippocampal CA1 neurons, suggesting a possible protection mechanism from excitotoxicity by circulating glutamate in SFO neurons.

A Distributed Trust Model Based on Reputation Management of Peers for P2P VoD Services

  • Huang, Guimin;Hu, Min;Zhou, Ya;Liu, Pingshan;Zhang, Yanchun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권9호
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    • pp.2285-2301
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    • 2012
  • Peer-to-Peer (P2P) networks are becoming more and more popular in video content delivery services, such as Video on Demand (VoD). Scalability feature of P2P allows a higher number of simultaneous users at a given server load and bandwidth to use stream service. However, the quality of service (QoS) in these networks is difficult to be guaranteed because of the free-riding problem that nodes download the recourses while never uploading recourses, which degrades the performance of P2P VoD networks. In this paper, a distributed trust model is designed to reduce node's free-riding phenomenon in P2P VoD networks. In this model, the P2P network is abstracted to be a super node hierarchical structure to monitor the reputation of nodes. In order to calculate the reputation of nodes, the Hidden Markov Model (HMM) is introduced in this paper. Besides, a distinction algorithm is proposed to distinguish the free-riders and malicious nodes. The free-riders are the nodes which have a low frequency to free-ride. And the malicious nodes have a high frequency to free-ride. The distinction algorithm takes different measures to response to the request of these two kinds of free-riders. The simulation results demonstrate that this proposed trust model can improve QoS effectively in P2P VoD networks.

Sever Selection Schemes Considering Node Status For a Fault-Tolerant Streaming Service on a Peer-to-Peer Network

  • Kim, Hyun-Joo;Kang, Soo-Yong;Yeom, Heon-Y.
    • Journal of Information Processing Systems
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    • 제2권1호
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    • pp.6-12
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    • 2006
  • Peer-to-Peer (P2P) networks are attracting considerable research interest because of their scalability and high performance relative to cost. One of the important services on a P2P network is the streaming service. However, because each node in the P2P network is autonomous, it is difficult to provide a stable streaming service on the network. Therefore, for a stable streaming service on the P2P network, a fault-tolerant scheme must be provided. In this paper, we propose two new node selection schemes, Playback Node First (PNF) and Playback Node first with Prefetching (PNF-P) that can be used for a service migration-based fault-tolerant streaming service. The proposed schemes exploit the fact that the failure probability of a node currently being served is lower than that of a node not being served. Simulation results show that the proposed schemes outperform traditional node selection schemes.

인산염 이온 형태에 의한 pH 변량 모형 (pH Variance Model Depending on Phosphate Ion Form)

  • 소재우;소순일;남상용
    • 원예과학기술지
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    • 제33권6호
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    • pp.854-859
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    • 2015
  • 본 시험은 배양액 내 pH 변화에 따른 이온과 EC의 모형을 구명하고자 수행하였다. 배양액 내 $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 따른 pH가 변하는데, pH 4.0-5.0은 EC의 변량이 상승하고, pH 5.0-7.0은 EC의 변량이 완만하고, pH 7.0-8.0은 다시 상승하였다. 배양액 내 다량원소의 변량을 보면, pH가 상승할수록 K, Ca, N, P의 이온 농도도 증가하는데, 특히 K과 P의 변량이 크게 나타났다. 반면 Mg와 S의 변량은 일정하게 유지되었다. 배양액의 IBM(ion balance model)에 따른 분석에서, EC의 변량은 크게 변하지 않고, 이온의 균형점이 a분면에서 d분면으로 이동하면 pH가 상승하면서 음이온 보다 양이온이 증가하는 것으로 나타났다. 또한 pH 변량이 높을수록 EC 중앙선으로부터 멀어져 배양액의 이온 불균형이 증가되었다. $HPO_4{^{-2}}$$H_2PO_4{^-}$의 변량에 대한 K와 Ca의 당량비 보정은 pH가 증가할수록 K는 감소하지만 Ca는 증가하였고, EC 변량의 영향보다 큰 것으로 나타났다. K와 Ca의 당량비 보정에 따른 pH 변량은 0.97의 이차 다항식 상관모형을 나타냈다. 본 연구를 통해 인산염의 구배에 따른 pH, 이온, EC의 변량에 대하여 pH 변량 모형이 구명되었다.

Chlamydomonas sp. 유래 mycosporine-like amino acid 혼합물의 항주름 활성 (Anti-corrugation activity of micosporine-like amino acid mixtures from Chlamydomonas sp.)

  • 서승석;서효현;이정훈;황진익;박미례;모상현;이택견
    • 한국산학기술학회논문지
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    • 제15권8호
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    • pp.5393-5399
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    • 2014
  • 미세조류 유래 mycosporine-like amino acids (MAAs) 혼합물의 항주름활성을 분석하기 위하여 type I procollagen, elastin 및 involucrin 유전자 발현분석을 실시하였다. Chlamydomonas sp.를 80% 에탄올로 추출하고, 컬럼을 통해 분획물을 정제하고, HPLC 분석을 통해 asterina 330+palythine (A+P) 및 shinorine+palythine (S+P) 혼합물을 정제하였다. MTT assay 결과 A+P 및 S+P는 0.1 mg/mL까지 세포독성을 나타내지 않았다. UV에 노출된 섬유아세포에 대한 MAAs 혼합물의 영향을 분석하였을 때, 0.05 mg/mL A+P 및 0.01 mg/mL S+P 농도에서 각각 2.7 및 3.6 배 PCOLCE mRNAs 발현이 증가하였다. Elastin 유전자는 0.01 mg/mL의 A+P 및 S+P를 처리하였을 때 각각 5.59배 및 3.1배 발현이 증가하였다. 특히 0.01 mg/mL의 A+P 및 S+P 농도에서 involucrin mRNAs 발현이 UV 처리된 대조구와 비교하였을 때 5배 및 2.5배 감소하였다. 결론적으로 Chlamydomonas sp. 유래 MAAs 혼합물은 주름개선용 기능성 화장품 개발을 위한 소재로써의 가능성이 충분한 것으로 판단되었다.

P(MAA-co-PEGMA) 수화젤의 조성과 탑재 pH가 화장품 활성물질의 탑재효율에 미치는 영향 (Effect of P(MAA-co-PEGMA) Hydrogel Compositions and Loading pH on the Loading Efficiency of Cosmetic Active Agents)

  • 이은미;김규식;김범상
    • 폴리머
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    • 제33권5호
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    • pp.441-445
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    • 2009
  • 본 연구에서는 알부틴, ascorbic acid, 아데노신 등과 같은 화장품 활성물질들을 주변 pH 변화에 따라서 선택적으로 방출하게 하는 지능형 전달시스템을 개발하기 위하여, pH 감응성 P(MAA-co-PEGMA) 수화젤을 분산 광중합을 이용하여 평균 크기 약 $2{\mu}m$의 구형 입자로 합성하였으며, 수화젤 입자는 수화젤의 $pK_a$인 PH 5를 전후로 하여 급격한 팽윤비의 변화를 보여주었다. P (MAA-co-PEGMA) 수화젤에 대한 활성물질들의 탑재에 영향을 미치는 요인들을 알아내기 위하여, 수화젤의 MAA와 EG의 조성과 탑재 pH에 따른 활성물질들의 탑재효율을 조사하였다. 수화젤을 구성하는 MAA와 EG의 조성 중 MAA의 함량이 감소함에 따라서 활성물질들의 탑재효율이 증가하였으며, 탑재 pH에 따른 실험에서는 수화젤과 활성물질들 사이에 형성되는 정전기적 반발력이 최소가 되는 pH보다는 수화젤의 팽윤비가 높게 되는 pH에서 탑재효율이 더 높게 나타났다.

Variety and phosphate fertilizer dose effect on nutrient composition, in vitro digestibility and feeding value of cowpea haulm

  • Ansah, Terry;Algma, Henry Ayindoh;Dei, Herbert Kwabla
    • Journal of Animal Science and Technology
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    • 제58권6호
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    • pp.19.1-19.7
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    • 2016
  • Background: Cowpea (Vigna unguiculata [L.]) is a legume cultivated throughout most tropical countries and is valued as food and feed for human and livestock respectively. The search for an improved cowpea variety has been on-going with the aim of improving traits such as grain yield, drought and pest resistance. But no information exist on the feeding value of these improved varieties. Phosphate (P) fertilizer application is recommended to augment grain yield in grain legumes but data on the effect of P fertilizer on haulm quality is limited. Results: Two separate experiments were conducted to determine the effect of P fertilizer dose on the nutritive value of haulms from different cowpea varieties (V). In experiment 1, effect of three P doses (30, 60 and 90 kg $P_2O_5/ha$) on in vitro gas production (IVGP) characteristics, concentrations of digestible organic matter (DOM), crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of haulms from five cowpea varieties (Zaayura-SARC 4-75, Songotra-IT97K-499-35, Hewale-IT93K-192-4, IT99K 573-1-1 and Asomdwe-IT94K-410-2) were investigated using the $3(P){\times}5(V)$ factorial treatment arrangements in a completely randomized design. In experiment 2, the effects of two P doses (30 and 90 kg $P_2O_5/ha$) and two varieties (Zaayura-SARC 4-75 and Hewale-IT93K-192-4) on the voluntary feed intake, live weight, haematology and carcass characteristics of Djallonke lambs were also assessed using a $2(P){\times}2(V)$ factorial treatment arrangement. The $V{\times}P$ interaction significantly affected CP, NDF and ADF with CP concentration increasing with increase in P doses in Zaayura-SARC 4-75 and Asomdwe-IT94K-410-2. Whilst an increase (P < 0.05) in NDF was observed in Songotra-IT97K-499-35and Asomdwe-IT94K-410-2 as P doses increased, the other V only increased from P dose 30 to 60 kg/ha and declined at P dose 90 kg/ha. The ADF decreased (P < 0.05) with increase in P dose for all V with the exception of Songotra-IT97K-499-35. There was a significant V effect on DOM with the highest reported in Zaayura-SARC 4-75 (43.44 %). Daily DM intake, carcass length and blood urea nitrogen of the lambs were significantly affected by the V x P interaction. There was a significant V effect on globulin and P effect on live weight at slaughter, dressed weight, chuck, leg, loin, rib and flank and liver and lungs. Conclusion: It can be concluded that nutrient concentrations of cowpea haulms were positively influenced by different P dose and varieties with favorable effects on growth, haematology and carcass composition of lambs. Varieties Zaayura-SARC 4-75 and Hewale-IT93K-192-4 at P dose at 90 kg/ha are recommended to enhance growth performance and carcass yield of Djallonke lambs.

CERTAIN GENERALIZED THORN GRAPHS AND THEIR WIENER INDICES

  • Kathiresan, KM.;Parameswaran, C.
    • Journal of applied mathematics & informatics
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    • 제30권5_6호
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    • pp.793-807
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    • 2012
  • If G is any connected graph of order p; then the thorn graph $G_p^*$ with code ($n_1$, $n_2$, ${\cdots}$, $n_p$) is obtained by adding $n_i$ pendent vertices to each $i^{th}$ vertex of G. By treating the pendent edge of a thorn graph as $P_2$, $K_2$, $K_{1,1}$, $K_1{\circ}K_1$ or $P_1{\circ}K_1$, we generalize a thorn graph by replacing $P_2$ by $P_m$, $K_2$ by $K_m$, $K_{1,1}$ by $K_{m,n}$, $K_1{\circ}K_1$ by $K_m{\circ}K_1$ and $P_1{\circ}K_1$ by $P_m{\circ}K_1$ and their respective generalized thorn graphs are denoted by $G_P$, $G_K$, $G_B$, $G_{KK}$ and $G_{PK}$ respectively. Many chemical compounds can be treated as $G_P$, $G_K$, $G_B$, $G_{KK}$ and $G_{PK}$ of some graphs in graph theory. In this paper, we obtain the bounds of the wiener index for these generalization of thorn graphs.