메뉴 건너뛰기




Volumn 28, Issue 1, 2015, Pages 116-125

Absorption, distribution, metabolism, excretion, and toxicity evaluation in drug discovery. 14. Prediction of human pregnane X receptor activators by using naive bayesian classification technique

Author keywords

[No Author keywords available]

Indexed keywords

ALKANE DERIVATIVE; CELL NUCLEUS RECEPTOR; CHEMICAL COMPOUND; HALOGEN; HORMONE RECEPTOR STIMULATING AGENT; NITROGEN; PREGNANE X RECEPTOR; PREGNANE X RECEPTOR ACTIVATOR; UNCLASSIFIED DRUG; STEROID RECEPTOR;

EID: 84922445961     PISSN: 0893228X     EISSN: 15205010     Source Type: Journal    
DOI: 10.1021/tx500389q     Document Type: Article
Times cited : (33)

References (56)
  • 1
    • 0035976638 scopus 로고    scopus 로고
    • Nuclear receptors and lipid physiology: Opening the X-files
    • Chawla, A., Repa, J. J., Evans, R. M., and Mangelsdorf, D. J. (2001) Nuclear receptors and lipid physiology: Opening the X-files Science 294, 1866-1870
    • (2001) Science , vol.294 , pp. 1866-1870
    • Chawla, A.1    Repa, J.J.2    Evans, R.M.3    Mangelsdorf, D.J.4
  • 2
    • 84863820598 scopus 로고    scopus 로고
    • QSAR model for human pregnane X receptor (PXR) binding: Screening of environmental chemicals and correlations with genotoxicity, endocrine disruption and teratogenicity
    • Dybdahl, M., Nikolov, N. G., Wedebye, E. B., Jónsdóttir, S. Ó., and Niemelä, J. R. (2012) QSAR model for human pregnane X receptor (PXR) binding: Screening of environmental chemicals and correlations with genotoxicity, endocrine disruption and teratogenicity Toxicol. Appl. Pharmacol. 262, 301-309
    • (2012) Toxicol. Appl. Pharmacol. , vol.262 , pp. 301-309
    • Dybdahl, M.1    Nikolov, N.G.2    Wedebye, E.B.3    Jónsdóttir S.Ó.4    Niemelä, J.R.5
  • 3
    • 0032169485 scopus 로고    scopus 로고
    • The human orphan nuclear receptor PXR is activated by compounds that regulate CYP3A4 gene expression and cause drug interactions
    • Lehmann, J. M., McKee, D. D., Watson, M. A., Willson, T. M., Moore, J. T., and Kliewer, S. A. (1998) The human orphan nuclear receptor PXR is activated by compounds that regulate CYP3A4 gene expression and cause drug interactions J. Clin. Invest. 102, 1016
    • (1998) J. Clin. Invest. , vol.102 , pp. 1016
    • Lehmann, J.M.1    McKee, D.D.2    Watson, M.A.3    Willson, T.M.4    Moore, J.T.5    Kliewer, S.A.6
  • 5
    • 0036799870 scopus 로고    scopus 로고
    • The nuclear pregnane X receptor: A key regulator of xenobiotic metabolism
    • Kliewer, S. A., Goodwin, B., and Willson, T. M. (2002) The nuclear pregnane X receptor: A key regulator of xenobiotic metabolism Endocr. Rev. 23, 687-702
    • (2002) Endocr. Rev. , vol.23 , pp. 687-702
    • Kliewer, S.A.1    Goodwin, B.2    Willson, T.M.3
  • 6
    • 1542327276 scopus 로고    scopus 로고
    • Predicting undesirable drug interactions with promiscuous proteins in silico
    • Ekins, S. (2004) Predicting undesirable drug interactions with promiscuous proteins in silico Drug Discovery Today 9, 276-285
    • (2004) Drug Discovery Today , vol.9 , pp. 276-285
    • Ekins, S.1
  • 10
    • 0034676513 scopus 로고    scopus 로고
    • Use of the nuclear receptor PXR to predict drug interactions
    • Moore, J. T. and Kliewer, S. A. (2000) Use of the nuclear receptor PXR to predict drug interactions Toxicology 153, 1-10
    • (2000) Toxicology , vol.153 , pp. 1-10
    • Moore, J.T.1    Kliewer, S.A.2
  • 11
    • 0036136534 scopus 로고    scopus 로고
    • A pharmacophore for human pregnane X receptor ligands
    • Ekins, S. and Erickson, J. A. (2002) A pharmacophore for human pregnane X receptor ligands Drug Metab. Dispos. 30, 96-99
    • (2002) Drug Metab. Dispos. , vol.30 , pp. 96-99
    • Ekins, S.1    Erickson, J.A.2
  • 12
    • 0023836595 scopus 로고
    • Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes
    • Zimniak, P., Radominska, A., Zimniak, M., and Lester, R. (1988) Formation of three types of glucuronides of 6-hydroxy bile acids by rat liver microsomes J. Lipid. Res. 29, 183-190
    • (1988) J. Lipid. Res. , vol.29 , pp. 183-190
    • Zimniak, P.1    Radominska, A.2    Zimniak, M.3    Lester, R.4
  • 14
    • 53849093733 scopus 로고    scopus 로고
    • Current industrial practices in assessing CYP450 enzyme induction: Preclinical and clinical
    • Sinz, M., Wallace, G., and Sahi, J. (2008) Current industrial practices in assessing CYP450 enzyme induction: preclinical and clinical AAPS J. 10, 391-400
    • (2008) AAPS J. , vol.10 , pp. 391-400
    • Sinz, M.1    Wallace, G.2    Sahi, J.3
  • 17
    • 33845870927 scopus 로고    scopus 로고
    • In Silico Prediction of Pregnane X Receptor Activators by Machine Learning Approache
    • Ung, C. Y., Li, H., Yap, C. W., and Chen, Y. Z. (2007) In Silico Prediction of Pregnane X Receptor Activators by Machine Learning Approache Mol. Pharmacol. 71, 158-168
    • (2007) Mol. Pharmacol. , vol.71 , pp. 158-168
    • Ung, C.Y.1    Li, H.2    Yap, C.W.3    Chen, Y.Z.4
  • 19
    • 61349196018 scopus 로고    scopus 로고
    • Hybrid scoring and classification approaches to predict human pregnane X receptor activators
    • Kortagere, S., Chekmarev, D., Welsh, W. J., and Ekins, S. (2009) Hybrid scoring and classification approaches to predict human pregnane X receptor activators Pharm. Res. 26, 1001-1011
    • (2009) Pharm. Res. , vol.26 , pp. 1001-1011
    • Kortagere, S.1    Chekmarev, D.2    Welsh, W.J.3    Ekins, S.4
  • 20
    • 80054726684 scopus 로고    scopus 로고
    • Predicting Activation of the Promiscuous Human Pregnane X Receptor by Pharmacophore Ensemble/Support Vector Machine Approach
    • Chen, C.-N., Shih, Y.-H., Ding, Y.-L., and Leong, M. K. (2011) Predicting Activation of the Promiscuous Human Pregnane X Receptor by Pharmacophore Ensemble/Support Vector Machine Approach Chem. Res. Toxicol. 24, 1765-1778
    • (2011) Chem. Res. Toxicol. , vol.24 , pp. 1765-1778
    • Chen, C.-N.1    Shih, Y.-H.2    Ding, Y.-L.3    Leong, M.K.4
  • 21
    • 79251516763 scopus 로고    scopus 로고
    • Identification and validation of novel human pregnane X receptor activators among prescribed drugs via ligand-based virtual screening
    • Pan, Y., Li, L., Kim, G., Ekins, S., Wang, H., and Swaan, P. W. (2011) Identification and validation of novel human pregnane X receptor activators among prescribed drugs via ligand-based virtual screening Drug Metab. Dispos. 39, 337-344
    • (2011) Drug Metab. Dispos. , vol.39 , pp. 337-344
    • Pan, Y.1    Li, L.2    Kim, G.3    Ekins, S.4    Wang, H.5    Swaan, P.W.6
  • 22
    • 84887615741 scopus 로고    scopus 로고
    • Molecular insights into the promiscuous interaction of human pregnane X receptor (hPXR) with diverse environmental chemicals and drug compounds
    • Chen, S., He, N., Chen, W., Sun, F., Li, L., Deng, R., and Hu, Y. (2014) Molecular insights into the promiscuous interaction of human pregnane X receptor (hPXR) with diverse environmental chemicals and drug compounds Chemosphere 96, 138-145
    • (2014) Chemosphere , vol.96 , pp. 138-145
    • Chen, S.1    He, N.2    Chen, W.3    Sun, F.4    Li, L.5    Deng, R.6    Hu, Y.7
  • 23
    • 0036643983 scopus 로고    scopus 로고
    • Quantitative structure-activity relationships for inducers of cytochromes P450 and nuclear receptor ligands involved in P450 regulation within the CYP1, CYP2, CYP3 and CYP4 families
    • Lewis, D., Jacobs, M., Dickins, M., and Lake, B. (2002) Quantitative structure-activity relationships for inducers of cytochromes P450 and nuclear receptor ligands involved in P450 regulation within the CYP1, CYP2, CYP3 and CYP4 families Toxicology 176, 51-57
    • (2002) Toxicology , vol.176 , pp. 51-57
    • Lewis, D.1    Jacobs, M.2    Dickins, M.3    Lake, B.4
  • 24
    • 0037424603 scopus 로고    scopus 로고
    • QSAR models in receptor-mediated effects: The nuclear receptor superfamily
    • Fang, H., Tong, W., Welsh, W. J., and Sheehan, D. M. (2003) QSAR models in receptor-mediated effects: The nuclear receptor superfamily J. Mol. Struct.: THEOCHEM 622, 113-125
    • (2003) J. Mol. Struct.: THEOCHEM , vol.622 , pp. 113-125
    • Fang, H.1    Tong, W.2    Welsh, W.J.3    Sheehan, D.M.4
  • 25
    • 0142042800 scopus 로고    scopus 로고
    • Prediction of human drug metabolizing enzyme induction
    • Mankowski, D. C. and Ekins, S. (2003) Prediction of human drug metabolizing enzyme induction Curr. Drug Metab. 4, 381-391
    • (2003) Curr. Drug Metab. , vol.4 , pp. 381-391
    • Mankowski, D.C.1    Ekins, S.2
  • 26
    • 18444374978 scopus 로고    scopus 로고
    • The identification of ligand features essential for PXR activation by pharmacophore modeling
    • Schuster, D. and Langer, T. (2005) The identification of ligand features essential for PXR activation by pharmacophore modeling J. Chem. Inf. Model. 45, 431-439
    • (2005) J. Chem. Inf. Model. , vol.45 , pp. 431-439
    • Schuster, D.1    Langer, T.2
  • 27
    • 33746706762 scopus 로고    scopus 로고
    • PXR and CAR: Nuclear receptors which play a pivotal role in drug disposition and chemical toxicity
    • Stanley, L. A., Horsburgh, B. C., Ross, J., Scheer, N., and Wolf, C. R. (2006) PXR and CAR: Nuclear receptors which play a pivotal role in drug disposition and chemical toxicity Drug Metab. Rev. 38, 515-597
    • (2006) Drug Metab. Rev. , vol.38 , pp. 515-597
    • Stanley, L.A.1    Horsburgh, B.C.2    Ross, J.3    Scheer, N.4    Wolf, C.R.5
  • 30
    • 0023913120 scopus 로고
    • The steroid and thyroid hormone receptor superfamily
    • Evans, R. M. (1988) The steroid and thyroid hormone receptor superfamily Science 240, 889-895
    • (1988) Science , vol.240 , pp. 889-895
    • Evans, R.M.1
  • 32
    • 33646517938 scopus 로고    scopus 로고
    • Evaluation of 170 xenobiotics as transactivators of human pregnane X receptor (hPXR) and correlation to known CYP3A4 drug interactions
    • Sinz, M., Kim, S., Zhu, Z., Chen, T., Anthony, M., Dickinson, K., and Rodrigues, A. D. (2006) Evaluation of 170 xenobiotics as transactivators of human pregnane X receptor (hPXR) and correlation to known CYP3A4 drug interactions Curr. Drug Metab. 7, 375-388
    • (2006) Curr. Drug Metab. , vol.7 , pp. 375-388
    • Sinz, M.1    Kim, S.2    Zhu, Z.3    Chen, T.4    Anthony, M.5    Dickinson, K.6    Rodrigues, A.D.7
  • 34
    • 69749083669 scopus 로고    scopus 로고
    • Nuclear receptors CAR and PXR: Molecular, functional, and biomedical aspects
    • di Masi, A., De Marinis, E., Ascenzi, P., and Marino, M. (2009) Nuclear receptors CAR and PXR: Molecular, functional, and biomedical aspects Mol. Aspects Med. 30, 297-343
    • (2009) Mol. Aspects Med. , vol.30 , pp. 297-343
    • Di Masi, A.1    De Marinis, E.2    Ascenzi, P.3    Marino, M.4
  • 35
    • 84866249554 scopus 로고    scopus 로고
    • Development of in silico filters to predict activation of the pregnane X receptor (PXR) by structurally diverse drug-like molecules
    • Matter, H., Anger, L. T., Giegerich, C., Guessregen, S., Hessler, G., and Baringhaus, K.-H. (2012) Development of in silico filters to predict activation of the pregnane X receptor (PXR) by structurally diverse drug-like molecules Bioorg. Med. Chem. 20, 5352-5365
    • (2012) Bioorg. Med. Chem. , vol.20 , pp. 5352-5365
    • Matter, H.1    Anger, L.T.2    Giegerich, C.3    Guessregen, S.4    Hessler, G.5    Baringhaus, K.-H.6
  • 36
    • 5544242529 scopus 로고    scopus 로고
    • MMFF VI. MMFF94s option for energy minimization studies
    • Halgren, T. A. (1999) MMFF VI. MMFF94s option for energy minimization studies J. Comput. Chem. 20, 720-729
    • (1999) J. Comput. Chem. , vol.20 , pp. 720-729
    • Halgren, T.A.1
  • 37
    • 84922436103 scopus 로고    scopus 로고
    • SYBYL molecular simulation package, Certara Inc. St. Louis
    • SYBYL molecular simulation package, Certara Inc., St. Louis, 2014, http://www.certara.com.
    • (2014)
  • 38
    • 0000381930 scopus 로고    scopus 로고
    • Prediction of hydrophobic (lipophilic) properties of small organic molecules using fragmental methods: An analysis of ALOGP and CLOGP methods
    • Ghose, A. K., Viswanadhan, V. N., and Wendoloski, J. J. (1998) Prediction of hydrophobic (lipophilic) properties of small organic molecules using fragmental methods: An analysis of ALOGP and CLOGP methods J. Phys. Chem. A 102, 3762-3772
    • (1998) J. Phys. Chem. A , vol.102 , pp. 3762-3772
    • Ghose, A.K.1    Viswanadhan, V.N.2    Wendoloski, J.J.3
  • 39
    • 0035526162 scopus 로고    scopus 로고
    • Estimation of aqueous solubility of chemical compounds using E-state indices
    • Tetko, I. V., Tanchuk, V. Y., Kasheva, T. N., and Villa, A. E. P. (2001) Estimation of aqueous solubility of chemical compounds using E-state indices J. Chem. Inf. Comput. Sci. 41, 1488-1493
    • (2001) J. Chem. Inf. Comput. Sci. , vol.41 , pp. 1488-1493
    • Tetko, I.V.1    Tanchuk, V.Y.2    Kasheva, T.N.3    Villa, A.E.P.4
  • 40
    • 84922467418 scopus 로고    scopus 로고
    • Discovery Studio 3.1 Guide, Accelrys Inc. San Diego
    • Discovery Studio 3.1 Guide, Accelrys Inc., San Diego, 2012, http://www.accelrys.com.
    • (2012)
  • 41
    • 0034625096 scopus 로고    scopus 로고
    • Molecular fields in quantitative structure-permeation relationships: The VolSurf approach
    • Cruciani, C., Crivori, P., Carrupt, P. A., and Testa, B. (2000) Molecular fields in quantitative structure-permeation relationships: the VolSurf approach J. Mol. Struct.: THEOCHEM 503, 17-30
    • (2000) J. Mol. Struct.: THEOCHEM , vol.503 , pp. 17-30
    • Cruciani, C.1    Crivori, P.2    Carrupt, P.A.3    Testa, B.4
  • 42
    • 84922455665 scopus 로고    scopus 로고
    • MOE molecular simulation package, Chemical Computing Group Inc. Montreal, Candada
    • MOE molecular simulation package, Chemical Computing Group Inc., Montreal, Candada, 2010. http://www.chemcomp.com.
    • (2010)
  • 43
    • 33751249304 scopus 로고    scopus 로고
    • Application of data mining approaches to drug delivery
    • Ekins, S., Shimada, J., and Chang, C. (2006) Application of data mining approaches to drug delivery Adv. Drug Delivery Rev. 58, 1409-1430
    • (2006) Adv. Drug Delivery Rev. , vol.58 , pp. 1409-1430
    • Ekins, S.1    Shimada, J.2    Chang, C.3
  • 44
    • 26944503021 scopus 로고    scopus 로고
    • Using extended-connectivity fingerprints with Laplacian-modified Bayesian analysis in high-throughput screening follow-up
    • Rogers, D., Brown, R. D., and Hahn, M. (2005) Using extended-connectivity fingerprints with Laplacian-modified Bayesian analysis in high-throughput screening follow-up J. Biomol. Screening 10, 682-686
    • (2005) J. Biomol. Screening , vol.10 , pp. 682-686
    • Rogers, D.1    Brown, R.D.2    Hahn, M.3
  • 45
    • 79958270321 scopus 로고    scopus 로고
    • ADME evaluation in drug discovery. 10. Predictions of P-glycoprotein inhibitors using recursive partitioning and naive Bayesian classification techniques
    • Chen, L., Li, Y., Zhao, Q., Peng, H., and Hou, T. (2011) ADME evaluation in drug discovery. 10. Predictions of P-glycoprotein inhibitors using recursive partitioning and naive Bayesian classification techniques Mol. Pharmaceutics 8, 889-900
    • (2011) Mol. Pharmaceutics , vol.8 , pp. 889-900
    • Chen, L.1    Li, Y.2    Zhao, Q.3    Peng, H.4    Hou, T.5
  • 46
    • 0018424479 scopus 로고
    • Describing the Validity of Carcinogen Screening-Tests
    • Cooper, J. A., Saracci, R., and Cole, P. (1979) Describing the Validity of Carcinogen Screening-Tests Br. J. Cancer 39, 87-89
    • (1979) Br. J. Cancer , vol.39 , pp. 87-89
    • Cooper, J.A.1    Saracci, R.2    Cole, P.3
  • 47
    • 84859269331 scopus 로고    scopus 로고
    • Computational models for predicting substrates or inhibitors of P-glycoprotein
    • Chen, L., Li, Y., Yu, H., Zhang, L., and Hou, T. (2012) Computational models for predicting substrates or inhibitors of P-glycoprotein Drug Discovery Today 17, 343-351
    • (2012) Drug Discovery Today , vol.17 , pp. 343-351
    • Chen, L.1    Li, Y.2    Yu, H.3    Zhang, L.4    Hou, T.5
  • 48
    • 84870177359 scopus 로고    scopus 로고
    • Drug-likeness Analysis of Traditional Chinese Medicines: Prediction of Drug-likeness Using Machine Learning Approaches
    • Tian, S., Wang, J., Li, Y., Xu, X., and Hou, T. (2012) Drug-likeness Analysis of Traditional Chinese Medicines: Prediction of Drug-likeness Using Machine Learning Approaches Mol. Pharmaceutics 9, 2875-2886
    • (2012) Mol. Pharmaceutics , vol.9 , pp. 2875-2886
    • Tian, S.1    Wang, J.2    Li, Y.3    Xu, X.4    Hou, T.5
  • 49
    • 84859345561 scopus 로고    scopus 로고
    • ADMET Evaluation in Drug Discovery. 12. Development of Binary Classification Models for Prediction of hERG Potassium Channel Blockage
    • Wang, S., Li, Y., Wang, J., Chen, L., Zhang, L., Yu, H., and Hou, T. (2012) ADMET Evaluation in Drug Discovery. 12. Development of Binary Classification Models for Prediction of hERG Potassium Channel Blockage Mol. Pharmaceutics 9, 996-1010
    • (2012) Mol. Pharmaceutics , vol.9 , pp. 996-1010
    • Wang, S.1    Li, Y.2    Wang, J.3    Chen, L.4    Zhang, L.5    Yu, H.6    Hou, T.7
  • 50
    • 84880531818 scopus 로고    scopus 로고
    • Modeling Compound-Target Interaction Network of Traditional Chinese Medicines for Type II Diabetes Mellitus: Insight for Polypharmacology and Drug Design
    • Tian, S., Li, Y., Li, D., Xu, X., Wang, J., Zhang, Q., and Hou, T. (2013) Modeling Compound-Target Interaction Network of Traditional Chinese Medicines for Type II Diabetes Mellitus: Insight for Polypharmacology and Drug Design J. Chem. Inf. Model. 53, 1787-1803
    • (2013) J. Chem. Inf. Model. , vol.53 , pp. 1787-1803
    • Tian, S.1    Li, Y.2    Li, D.3    Xu, X.4    Wang, J.5    Zhang, Q.6    Hou, T.7
  • 51
    • 84887042090 scopus 로고    scopus 로고
    • Development and Evaluation of an Integrated Virtual Screening Strategy by Combining Molecular Docking and Pharmacophore Searching Based on Multiple Protein Structures
    • Tian, S., Sun, H., Li, Y., Pan, P., Li, D., and Hou, T. (2013) Development and Evaluation of an Integrated Virtual Screening Strategy by Combining Molecular Docking and Pharmacophore Searching Based on Multiple Protein Structures J. Chem. Inf. Model. 53, 2743-2756
    • (2013) J. Chem. Inf. Model. , vol.53 , pp. 2743-2756
    • Tian, S.1    Sun, H.2    Li, Y.3    Pan, P.4    Li, D.5    Hou, T.6
  • 52
    • 84881329253 scopus 로고    scopus 로고
    • Recent Developments in Computational Prediction of hERG Blockage
    • Wang, S., Li, Y., Xu, L., Li, D., and Hou, T. (2013) Recent Developments in Computational Prediction of hERG Blockage Curr. Top. Med. Chem. 13, 1317-1326
    • (2013) Curr. Top. Med. Chem. , vol.13 , pp. 1317-1326
    • Wang, S.1    Li, Y.2    Xu, L.3    Li, D.4    Hou, T.5
  • 53
    • 34247245174 scopus 로고    scopus 로고
    • ADME evaluation in drug discovery. 6. Can oral bioavailability in humans be effectively predicted by simple molecular property-based rules?
    • Hou, T. J., Wang, J. M., Zhang, W., and Xu, X. J. (2007) ADME evaluation in drug discovery. 6. Can oral bioavailability in humans be effectively predicted by simple molecular property-based rules? J. Chem. Inf. Model. 47, 460-463
    • (2007) J. Chem. Inf. Model. , vol.47 , pp. 460-463
    • Hou, T.J.1    Wang, J.M.2    Zhang, W.3    Xu, X.J.4
  • 54
    • 33846855555 scopus 로고    scopus 로고
    • ADME evaluation in drug discovery. 7. Prediction of oral absorption by correlation and classification
    • Hou, T. J., Wang, J. M., Zhang, W., and Xu, X. J. (2007) ADME evaluation in drug discovery. 7. Prediction of oral absorption by correlation and classification J. Chem. Inf. Model. 47, 208-218
    • (2007) J. Chem. Inf. Model. , vol.47 , pp. 208-218
    • Hou, T.J.1    Wang, J.M.2    Zhang, W.3    Xu, X.J.4
  • 55
    • 33748545599 scopus 로고    scopus 로고
    • Recent advances in computational prediction of drug absorption and permeability in drug discovery
    • Hou, T. J., Wang, J. M., Zhang, W., Wang, W., and Xu, X. (2006) Recent advances in computational prediction of drug absorption and permeability in drug discovery Curr. Med. Chem. 13, 2653-2667
    • (2006) Curr. Med. Chem. , vol.13 , pp. 2653-2667
    • Hou, T.J.1    Wang, J.M.2    Zhang, W.3    Wang, W.4    Xu, X.5
  • 56
    • 48949117177 scopus 로고    scopus 로고
    • Structure - ADME relationship: Still a long way to go?
    • Hou, T. and Wang, J. (2008) Structure-ADME relationship: Still a long way to go? Expert Opin. Drug Metab. Toxicol. 4, 759-770
    • (2008) Expert Opin. Drug Metab. Toxicol. , vol.4 , pp. 759-770
    • Hou, T.1    Wang, J.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.