SCOPUS 정보 검색 플랫폼

Volumn 12, Issue 22, 2010, Pages 5818-5823

Feasibility of in vivo15N MRS detection of hyperpolarized 15N labeled choline in rats

(9) Cudalbu, Cristina a Comment, Arnaud a,b Kurdzesau, Fiodar a,c van Heeswijk, Ruud B a Uffmann, Kai a Jannin, Sami a Denisov, Vladimir d Kirik, Deniz d Gruetter, Rolf a,b,e

a EPFL (Switzerland)

b UNIVERSITY OF LAUSANNE (Switzerland)

c PAUL SCHERRER INSTITUTE (Switzerland)

d LUND UNIVERSITY (Sweden)

e UNIVERSITY OF GENEVA (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

CHOLINE; NITROGEN;

ANIMAL; ARTICLE; CHEMISTRY; ISOTOPE LABELING; MALE; METHODOLOGY; NUCLEAR MAGNETIC RESONANCE IMAGING; RAT; SPRAGUE DAWLEY RAT;

ANIMALS; CHOLINE; ISOTOPE LABELING; MAGNETIC RESONANCE IMAGING; MALE; NITROGEN ISOTOPES; RATS; RATS, SPRAGUE-DAWLEY;

EID: 77952914139 PISSN: 14639076 EISSN: None Source Type: Journal
DOI: 10.1039/c002309b Document Type: Article

Times cited : (91)

References (58)

1
- 0026443850
- P. B. Barker, J. D. Glickson, R. N. Bryan Top. Magn. Reson. Imaging, 1993, 5, 32-45
- (1993) Top. Magn. Reson. Imaging , vol.5 , pp. 32-45
- Barker, P.B.¹ Glickson, J.D.² Bryan, R.N.³

2
- 0031985750
- P. J. Pouwels, J. Frahm Magn. Reson. Med., 1998, 39, 53-60
- (1998) Magn. Reson. Med. , vol.39 , pp. 53-60
- Pouwels, P.J.¹ Frahm, J.²

3
- 0028695478
- B. Ross, T. Michaelis Magn. Reson. Q, 1994, 10, 191-247
- (1994) Magn. Reson. Q , vol.10 , pp. 191-247
- Ross, B.¹ Michaelis, T.²

4
- 0036952304
- W. Moller-Hartmann, S. Herminghaus, T. Krings, G. Marquardt, H. Lanfermann, U. Pilatus, F. E. Zanella Neuroradiology, 2002, 44, 371-381
- (2002) Neuroradiology , vol.44 , pp. 371-381
- Moller-Hartmann, W.¹ Herminghaus, S.² Krings, T.³ Marquardt, G.⁴ Lanfermann, H.⁵ Pilatus, U.⁶ Zanella, F.E.⁷

5
- 0043131975
- F. A. Howe, K. S. Opstad NMR Biomed., 2003, 16, 123-131
- (2003) NMR Biomed. , vol.16 , pp. 123-131
- Howe, F.A.¹ Opstad, K.S.²

6
- 0026437870
- P. Narayan, J. Kurhanewicz Prostate, 1992, 21, s4, 43-50
- (1992) Prostate , vol.21 , Issue.S4 , pp. 43-50
- Narayan, P.¹ Kurhanewicz, J.²

7
- 0027462075
- F. Schick, H. Bongers, S. Kurz, W. I. Jung, M. Pfeffer, O. Lutz Magn. Reson. Med., 1993, 29, 38-43
- (1993) Magn. Reson. Med. , vol.29 , pp. 38-43
- Schick, F.¹ Bongers, H.² Kurz, S.³ Jung, W.I.⁴ Pfeffer, M.⁵ Lutz, O.⁶

8
- 0030056928
- J. Kurhanewicz, D. B. Vigneron, H. Hricak, P. Narayan, P. Carroll, S. J. Nelson Radiology, 1996, 198, 795-805
- (1996) Radiology , vol.198 , pp. 795-805
- Kurhanewicz, J.¹ Vigneron, D.B.² Hricak, H.³ Narayan, P.⁴ Carroll, P.⁵ Nelson, S.J.⁶

9
- 33749043078
- K. Glunde, C. Jie, Z. M. Bhujwalla Neoplasia, 2006, 8, 758-771
- (2006) Neoplasia , vol.8 , pp. 758-771
- Glunde, K.¹ Jie, C.² Bhujwalla, Z.M.³

10
- 0346829863
- M. A. Jacobs, P. B. Barker, P. A. Bottomley, Z. Bhujwalla, D. A. Bluemke J. Magn. Reson. Imaging, 2004, 19, 68-75
- (2004) J. Magn. Reson. Imaging , vol.19 , pp. 68-75
- Jacobs, M.A.¹ Barker, P.B.² Bottomley, P.A.³ Bhujwalla, Z.⁴ Bluemke, D.A.⁵

11
- 0034969284
- D. K. Yeung, H. S. Cheung, G. M. Tse Radiology, 2001, 220, 40-46
- (2001) Radiology , vol.220 , pp. 40-46
- Yeung, D.K.¹ Cheung, H.S.² Tse, G.M.³

12
- 0031713186
- J. R. Roebuck, K. M. Cecil, M. D. Schnall, R. E. Lenkinski Radiology, 1998, 209, 269-275
- (1998) Radiology , vol.209 , pp. 269-275
- Roebuck, J.R.¹ Cecil, K.M.² Schnall, M.D.³ Lenkinski, R.E.⁴

13
- 0032424029
- N. R. Jagannathan, M. Singh, V. Govindaraju, P. Raghunathan, O. Coshic, P. K. Julka, G. K. Rath NMR Biomed., 1998, 11, 414-422
- (1998) NMR Biomed. , vol.11 , pp. 414-422
- Jagannathan, N.R.¹ Singh, M.² Govindaraju, V.³ Raghunathan, P.⁴ Coshic, O.⁵ Julka, P.K.⁶ Rath, G.K.⁷

14
- 33750435528
- K. Glunde, N. J. Serkova Pharmacogenomics, 2006, 7, 1109-1123
- (2006) Pharmacogenomics , vol.7 , pp. 1109-1123
- Glunde, K.¹ Serkova, N.J.²

15
- 33845383242
- K. Glunde, M. A. Jacobs, Z. M. Bhujwalla Expert Rev. Mol. Diagn., 2006, 6, 821-829
- (2006) Expert Rev. Mol. Diagn. , vol.6 , pp. 821-829
- Glunde, K.¹ Jacobs, M.A.² Bhujwalla, Z.M.³

16
- 33750383279
- K. Glunde, E. Ackerstaff, N. Mori, M. A. Jacobs, Z. M. Bhujwalla Mol. Pharmaceutics, 2006, 3, 496-506
- (2006) Mol. Pharmaceutics , vol.3 , pp. 496-506
- Glunde, K.¹ Ackerstaff, E.² Mori, N.³ Jacobs, M.A.⁴ Bhujwalla, Z.M.⁵

17
- 7044228014
- S. Meisamy, P. J. Bolan, E. H. Baker, R. L. Bliss, E. Gulbahce, L. I. Everson, M. T. Nelson, T. H. Emory, T. M. Tuttle, D. Yee, M. Garwood Radiology, 2004, 233, 424-431
- (2004) Radiology , vol.233 , pp. 424-431
- Meisamy, S.¹ Bolan, P.J.² Baker, E.H.³ Bliss, R.L.⁴ Gulbahce, E.⁵ Everson, L.I.⁶ Nelson, M.T.⁷ Emory, T.H.⁸ Tuttle, T.M.⁹ Yee, D.¹⁰ Garwood, M.¹¹

18
- 0036186445
- M. Law, S. Cha, E. A. Knopp, G. Johnson, J. Arnett, A. W. Litt Radiology, 2002, 222, 715-721
- (2002) Radiology , vol.222 , pp. 715-721
- Law, M.¹ Cha, S.² Knopp, E.A.³ Johnson, G.⁴ Arnett, J.⁵ Litt, A.W.⁶

19
- 32544432882
- D. J. Manton, A. Chaturvedi, A. Hubbard, M. J. Lind, M. Lowry, A. Maraveyas, M. D. Pickles, D. J. Tozer, L. W. Turnbull Br. J. Cancer, 2006, 94, 427-435
- (2006) Br. J. Cancer , vol.94 , pp. 427-435
- Manton, D.J.¹ Chaturvedi, A.² Hubbard, A.³ Lind, M.J.⁴ Lowry, M.⁵ Maraveyas, A.⁶ Pickles, M.D.⁷ Tozer, D.J.⁸ Turnbull, L.W.⁹

20
- 0034087595
- J. Kurhanewicz, D. B. Vigneron, S. J. Nelson Neoplasia, 2000, 2, 166-189
- (2000) Neoplasia , vol.2 , pp. 166-189
- Kurhanewicz, J.¹ Vigneron, D.B.² Nelson, S.J.³

21
- 34548148983
- A. M. Groves, T. Win, S. B. Haim, P. J. Ell Lancet Oncol., 2007, 8, 822-830
- (2007) Lancet Oncol. , vol.8 , pp. 822-830
- Groves, A.M.¹ Win, T.² Haim, S.B.³ Ell, P.J.⁴

22
- 0031026448
- N. Shinoura, M. Nishijima, T. Hara, T. Haisa, H. Yamamoto, K. Fujii, I. Mitsui, N. Kosaka, T. Kondo Radiology, 1997, 202, 497-503
- (1997) Radiology , vol.202 , pp. 497-503
- Shinoura, N.¹ Nishijima, M.² Hara, T.³ Haisa, T.⁴ Yamamoto, H.⁵ Fujii, K.⁶ Mitsui, I.⁷ Kosaka, N.⁸ Kondo, T.⁹

23
- 0030990453
- T. Hara, N. Kosaka, N. Shinoura, T. Kondo J. Nucl. Med., 1997, 38, 842-847
- (1997) J. Nucl. Med. , vol.38 , pp. 842-847
- Hara, T.¹ Kosaka, N.² Shinoura, N.³ Kondo, T.⁴

24
- 0032077163
- J. Klein, A. Koppen, K. Loffelholz Neurochem. Int., 1998, 32, 479-485
- (1998) Neurochem. Int. , vol.32 , pp. 479-485
- Klein, J.¹ Koppen, A.² Loffelholz, K.³

25
- 0025740762
- J. Klein, A. Koppen, K. Loffelholz J. Neurochem., 1991, 57, 370-375
- (1991) J. Neurochem. , vol.57 , pp. 370-375
- Klein, J.¹ Koppen, A.² Loffelholz, K.³

26
- 0025111206
- J. Klein, A. Koppen, K. Loffelholz J. Neurochem., 1990, 55, 1231-1236
- (1990) J. Neurochem. , vol.55 , pp. 1231-1236
- Klein, J.¹ Koppen, A.² Loffelholz, K.³

27
- 0031795007
- R. Katz-Brull, R. Margalit, P. Bendel, H. Degani Mag. Reson. Mater. Phys. Biol. Med., 1998, 6, 44-52
- (1998) Mag. Reson. Mater. Phys. Biol. Med. , vol.6 , pp. 44-52
- Katz-Brull, R.¹ Margalit, R.² Bendel, P.³ Degani, H.⁴

28
- 0032588159
- K. Kanamori, B. D. Ross Magn. Reson. Med., 1999, 41, 456-463
- (1999) Magn. Reson. Med. , vol.41 , pp. 456-463
- Kanamori, K.¹ Ross, B.D.²

29
- 0027209260
- K. Kanamori, B. D. Ross Biochem. J., 1993, 293, Pt 2, 461-468
- (1993) Biochem. J. , vol.293 , pp. 461-468
- Kanamori, K.¹ Ross, B.D.²

30
- 0000633163
- G. M. Abragam A Rep. Prog. Phys., 1978, 41, 395-467
- (1978) Rep. Prog. Phys. , vol.41 , pp. 395-467
- Abragam, G.M.A.¹

31
- 0042763165
- J. H. Ardenkjaer-Larsen, B. Fridlund, A. Gram, G. Hansson, L. Hansson, M. H. Lerche, R. Servin, M. Thaning, K. Golman Proc. Natl. Acad. Sci. U. S. A., 2003, 100, 10158-10163
- (2003) Proc. Natl. Acad. Sci. U. S. A. , vol.100 , pp. 10158-10163
- Ardenkjaer-Larsen, J.H.¹ Fridlund, B.² Gram, A.³ Hansson, G.⁴ Hansson, L.⁵ Lerche, M.H.⁶ Servin, R.⁷ Thaning, M.⁸ Golman, K.⁹

32
- 45149112158
- F. A. Gallagher, M. I. Kettunen, S. E. Day, D. E. Hu, J. H. Ardenkjaer-Larsen, R. Zandt, P. R. Jensen, M. Karlsson, K. Golman, M. H. Lerche, K. M. Brindle Nature, 2008, 453, 940-943
- (2008) Nature , vol.453 , pp. 940-943
- Gallagher, F.A.¹ Kettunen, M.I.² Day, S.E.³ Hu, D.E.⁴ Ardenkjaer-Larsen, J.H.⁵ Zandt, R.⁶ Jensen, P.R.⁷ Karlsson, M.⁸ Golman, K.⁹ Lerche, M.H.¹⁰ Brindle, K.M.¹¹

33
- 33745824936
- K. Golman, J. S. Petersson Acad. Radiol., 2006, 13, 932-942
- (2006) Acad. Radiol. , vol.13 , pp. 932-942
- Golman, K.¹ Petersson, J.S.²

34
- 33845292936
- K. Golman, R. I. Zandt, M. Lerche, R. Pehrson, J. H. Ardenkjaer-Larsen Cancer Res., 2006, 66, 10855-10860
- (2006) Cancer Res. , vol.66 , pp. 10855-10860
- Golman, K.¹ Zandt, R.I.² Lerche, M.³ Pehrson, R.⁴ Ardenkjaer-Larsen, J.H.⁵

35
- 36148976010
- A. Comment, B. van den Brandt, K. Uffmann, F. Kurdzesau, S. Jannin, J. A. Konter, P. Hautle, W. T. H. Wenckebach, R. Gruetter, J. J. van der Klink Concepts Magn. Reson., Part B, 2007, 31B, 255-269
- (2007) Concepts Magn. Reson., Part B , vol.31 B , pp. 255-269
- Comment, A.¹ van den Brandt, B.² Uffmann, K.³ Kurdzesau, F.⁴ Jannin, S.⁵ Konter, J.A.⁶ Hautle, P.⁷ Wenckebach, W.T.H.⁸ Gruetter, R.⁹ van der Klink, J.J.¹⁰

36
- 85035242509
- M. L. Zierhut, Y. F. Yen, A. P. Chen, R. Bok, M. J. Albers, V. Zhang, J. Tropp, I. Park, D. B. Vigneron, J. Kurhanewicz, R. E. Hurd, S. J. Nelson J. Magn. Reson., 2009
- (2009) J. Magn. Reson.
- Zierhut, M.L.¹ Yen, Y.F.² Chen, A.P.³ Bok, R.⁴ Albers, M.J.⁵ Zhang, V.⁶ Tropp, J.⁷ Park, I.⁸ Vigneron, D.B.⁹ Kurhanewicz, J.¹⁰ Hurd, R.E.¹¹ Nelson, S.J.¹²

37
- 36849029752
- A. P. Chen, M. J. Albers, C. H. Cunningham, S. J. Kohler, Y. F. Yen, R. E. Hurd, J. Tropp, R. Bok, J. M. Pauly, S. J. Nelson, J. Kurhanewicz, D. B. Vigneron Magn. Reson. Med., 2007, 58, 1099-1106
- (2007) Magn. Reson. Med. , vol.58 , pp. 1099-1106
- Chen, A.P.¹ Albers, M.J.² Cunningham, C.H.³ Kohler, S.J.⁴ Yen, Y.F.⁵ Hurd, R.E.⁶ Tropp, J.⁷ Bok, R.⁸ Pauly, J.M.⁹ Nelson, S.J.¹⁰ Kurhanewicz, J.¹¹ Vigneron, D.B.¹²

38
- 67049134873
- R. B. van Heeswijk, K. Uffmann, A. Comment, F. Kurdzesau, C. Perazzolo, C. Cudalbu, S. Jannin, J. A. Konter, P. Hautle, B. van den Brandt, G. Navon, J. J. van der Klink, R. Gruetter Magn. Reson. Med., 2009, 61, 1489-1493
- (2009) Magn. Reson. Med. , vol.61 , pp. 1489-1493
- Van Heeswijk, R.B.¹ Uffmann, K.² Comment, A.³ Kurdzesau, F.⁴ Perazzolo, C.⁵ Cudalbu, C.⁶ Jannin, S.⁷ Konter, J.A.⁸ Hautle, P.⁹ van den Brandt, B.¹⁰ Navon, G.¹¹ van der Klink, J.J.¹² Gruetter, R.¹³

39
- 0028814636
- H. Middleton, R. D. Black, B. Saam, G. D. Cates, G. P. Cofer, R. Guenther, W. Happer, L. W. Hedlund, G. A. Johnson, K. Juvan, et al. Magn. Reson. Med., 1995, 33, 271-275
- (1995) Magn. Reson. Med. , vol.33 , pp. 271-275
- Middleton, H.¹ Black, R.D.² Saam, B.³ Cates, G.D.⁴ Cofer, G.P.⁵ Guenther, R.⁶ Happer, W.⁷ Hedlund, L.W.⁸ Johnson, G.A.⁹ Juvan, K.¹⁰

40
- 70450202944
- R. Sarkar, A. Comment, P. R. Vasos, S. Jannin, R. Gruetter, G. Bodenhausen, H. Hall, D. Kirik, V. P. Denisov J. Am. Chem. Soc., 2009, 131, 16014-16015
- (2009) J. Am. Chem. Soc. , vol.131 , pp. 16014-16015
- Sarkar, R.¹ Comment, A.² Vasos, P.R.³ Jannin, S.⁴ Gruetter, R.⁵ Bodenhausen, G.⁶ Hall, H.⁷ Kirik, D.⁸ Denisov, V.P.⁹

41
- 41849121889
- C. Gabellieri, S. Reynolds, A. Lavie, G. S. Payne, M. O. Leach, T. R. Eykyn J. Am. Chem. Soc., 2008, 130, 4598-4599
- (2008) J. Am. Chem. Soc. , vol.130 , pp. 4598-4599
- Gabellieri, C.¹ Reynolds, S.² Lavie, A.³ Payne, G.S.⁴ Leach, M.O.⁵ Eykyn, T.R.⁶

42
- 59849120390
- A. Comment, B. van den Brandt, K. Uffmann, F. Kurdzesau, S. Jannin, J. A. Konter, P. Hautle, W. T. Wenckebach, R. Gruetter, J. J. van der Klink Appl. Magn. Reson., 2008, 34, 313-319
- (2008) Appl. Magn. Reson. , vol.34 , pp. 313-319
- Comment, A.¹ van den Brandt, B.² Uffmann, K.³ Kurdzesau, F.⁴ Jannin, S.⁵ Konter, J.A.⁶ Hautle, P.⁷ Wenckebach, W.T.⁸ Gruetter, R.⁹ van der Klink, J.J.¹⁰

43
- 0345167988
- T. Ethofer, I. Mader, U. Seeger, G. Helms, M. Erb, W. Grodd, A. Ludolph, U. Klose Magn. Reson. Med., 2003, 50, 1296-1301
- (2003) Magn. Reson. Med. , vol.50 , pp. 1296-1301
- Ethofer, T.¹ Mader, I.² Seeger, U.³ Helms, G.⁴ Erb, M.⁵ Grodd, W.⁶ Ludolph, A.⁷ Klose, U.⁸

44
- 0023940517
- R. P. Shockley, J. C. LaManna Brain Res., 1988, 454, 170-178
- (1988) Brain Res. , vol.454 , pp. 170-178
- Shockley, R.P.¹ LaManna, J.C.²

45
- 0345528225
- L. Darrasse, J. C. Ginefri Biochimie, 2003, 85, 915-937
- (2003) Biochimie , vol.85 , pp. 915-937
- Darrasse, L.¹ Ginefri, J.C.²

46
- 0041836259
- K. Golman, J. H. Ardenkjaer-Larsen, J. S. Petersson, S. Mansson, I. Leunbach Proc. Natl. Acad. Sci. U. S. A., 2003, 100, 10435-10439
- (2003) Proc. Natl. Acad. Sci. U. S. A. , vol.100 , pp. 10435-10439
- Golman, K.¹ Ardenkjaer-Larsen, J.H.² Petersson, J.S.³ Mansson, S.⁴ Leunbach, I.⁵

47
- 33746625531
- K. Golman, R. in’t Zandt, M. Thaning Proc. Natl. Acad. Sci. U. S. A., 2006, 103, 11270-11275
- (2006) Proc. Natl. Acad. Sci. U. S. A. , vol.103 , pp. 11270-11275
- Golman, K.¹ In’t Zandt, R.² Thaning, M.³

48
- 77952892749
- F. Kurdzesau, B. van den Brandt, A. Comment, P. Hautle, S. Jannin, J. J. van der Klink, J. A. Konter J. Phys. D-Appl. Phys., 2008, 41.
- (2008) J. Phys. D-Appl. Phys. , pp. 41
- Kurdzesau, F.¹ van den Brandt, B.² Comment, A.³ Hautle, P.⁴ Jannin, S.⁵ Van der Klink, J.J.⁶ Konter, J.A.⁷

49
- 0025881720
- D. Gelvan, P. Saltman, S. R. Powell Proc. Natl. Acad. Sci. U. S. A., 1991, 88, 4680-4684
- (1991) Proc. Natl. Acad. Sci. U. S. A. , vol.88 , pp. 4680-4684
- Gelvan, D.¹ Saltman, P.² Powell, S.R.³

50
- 0029267363
- Y. Miura, A. Hamada, H. Utsumi Free Radical Res., 1995, 22, 209-214
- (1995) Free Radical Res. , vol.22 , pp. 209-214
- Miura, Y.¹ Hamada, A.² Utsumi, H.³

51
- 0037090116
- H. Li, L. Ma, C. J. Hsia, J. L. Zweier, P. Kuppusamy Free Radical Biol. Med., 2002, 32, 712-719
- (2002) Free Radical Biol. Med. , vol.32 , pp. 712-719
- Li, H.¹ Ma, L.² Hsia, C.J.³ Zweier, J.L.⁴ Kuppusamy, P.⁵

52
- 0030970081
- S. M. Hahn, F. J. Sullivan, A. M. DeLuca, C. M. Krishna, N. Wersto, D. Venzon, A. Russo, J. B. Mitchell Free Radical Biol. Med., 1997, 22, 1211-1216
- (1997) Free Radical Biol. Med. , vol.22 , pp. 1211-1216
- Hahn, S.M.¹ Sullivan, F.J.² DeLuca, A.M.³ Krishna, C.M.⁴ Wersto, N.⁵ Venzon, D.⁶ Russo, A.⁷ Mitchell, J.B.⁸

53
- 0032012581
- M. Terpstra, P. M. Andersen, R. Gruetter J. Magn. Reson., 1998, 131, 139-143
- (1998) J. Magn. Reson. , vol.131 , pp. 139-143
- Terpstra, M.¹ Andersen, P.M.² Gruetter, R.³

54
- 0342948677
- R. Gruetter, I. Tkac Magn. Reson. Med., 2000, 43, 319-323
- (2000) Magn. Reson. Med. , vol.43 , pp. 319-323
- Gruetter, R.¹ Tkac, I.²

55
- 44949273876
- M. Garwood, K. Yong J. Magn. Reson., 1991, 94, 511-525
- (1991) J. Magn. Reson. , vol.94 , pp. 511-525
- Garwood, M.¹ Yong, K.²

56
- 0346308381
- L. Vanhamme, A. van den Boogaart, S. Van Huffel J. Magn. Reson., 1997, 129, 35-43
- (1997) J. Magn. Reson. , vol.129 , pp. 35-43
- Vanhamme, L.¹ van den Boogaart, A.² Van Huffel, S.³

57
- 0035033455
- A. Naressi, C. Couturier, I. Castang, R. de Beer, D. Graveron-Demilly Comput. Biol. Med., 2001, 31, 269-286
- (2001) Comput. Biol. Med. , vol.31 , pp. 269-286
- Naressi, A.¹ Couturier, C.² Castang, I.³ de Beer, R.⁴ Graveron-Demilly, D.⁵

58
- 0034959967
- S. Cavassila, S. Deval, C. Huegen, D. van Ormondt, D. Graveron-Demilly NMR Biomed., 2001, 14, 278-283
- (2001) NMR Biomed. , vol.14 , pp. 278-283
- Cavassila, S.¹ Deval, S.² Huegen, C.³ van Ormondt, D.⁴ Graveron-Demilly, D.⁵

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.