SCIENCE DIRECT LUMINESCENCE ELSEVIER Journal of Luminescence 119-120(2006)132-136 www.elsevier.comple Infrared absorption of human breast tissues in vitro Chenglin Liu.b, Yuan Zhang, Xiaohui Yan, Xinyi Zhang C,, Chengxiang Li Wentao Yang, Daren Shi Department of Physics, Surface Physics Laboratory( National Key laboratory ) Synchrotre ation Research Center Fudan Unirersity, Shanghai 200433, China Physics Department of Yancheng Teachers'College, Yancheng 224002, China Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203, China d National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, china "Cancer Hospital, Medical Center, Fudan University, Shanghai 200032, China Available online 7 February 2006 Abstract The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared(SR-FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR)source, higher resolving power is achieved in SR-FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some pecific absorption peaks were found in breast cancer tissues by SR-FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer. C 2006 Elsevier B.V. All rights reserved Keywords: FTIR spectroscopy: Synchrotron radiation: Breast cancer Introduction disease has become more popular in China leading to great suffering for women. In the latest 5 years Breast cancer is a global killer of women. in China, the incidence of breast cancer per year Previously this cancer mainly occurred in the has increased almost three times, from 17 out of western countries, but in recent years, this frightful 100.000 52 out of 100.000. while the mean starting age of this cancer in China is 30 years old Corresponding author. Department of Physics, Surtace with its peak age from 40 to 49, which is 10-15 Radiation Research Center, Fudan University, Shanghai years earlier than in the US [1]. Unfortunately, 200433 China. Tel /fax: because of the late treatment, a part of patients, E-mailaddress:xy.zhang@fudan.edu.cn(X.Zhang) which is as high as about 35% in China, are 0022-2313/S-see front matter C 2006 Elsevier B.v. All rights reserved i:l0.l016 jalumin2005.12.050
Journal of Luminescence 119–120 (2006) 132–136 Infrared absorption of human breast tissues in vitro Chenglin Liua,b, Yuan Zhanga , Xiaohui Yana , Xinyi Zhanga,c,, Chengxiang Lid , Wentao Yange , Daren Shie a Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433, China b Physics Department of Yancheng Teachers’ College, Yancheng 224002, China c Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203, China d National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China e Cancer Hospital, Medical Center, Fudan University, Shanghai 200032, China Available online 7 February 2006 Abstract The spectral characteristics of human breast tissues in normal status and during different cancerous stages have been investigated by synchrotron radiation based Fourier transform infrared (SR–FTIR) absorption spectroscopy. Thanks to the excellent synchrotron radiation infrared (IR) source, higher resolving power is achieved in SR–FTIR absorption spectra than in conventional IR absorption measurements. Obvious variations in IR absorption spectrum of breast tissues were found as they change from healthy to diseased, or say in progression to cancer. On the other hand, some specific absorption peaks were found in breast cancer tissues by SR–FTIR spectroscopic methods. These spectral characteristics of breast tissue may help us in early diagnosis of breast cancer. r 2006 Elsevier B.V. All rights reserved. Keywords: FTIR spectroscopy; Synchrotron radiation; Breast cancer 1. Introduction Breast cancer is a global killer of women. Previously this cancer mainly occurred in the western countries, but in recent years, this frightful disease has become more popular in China leading to great suffering for women. In the latest 5 years in China, the incidence of breast cancer per year has increased almost three times, from 17 out of 100,000 to 52 out of 100,000, while the mean starting age of this cancer in China is 30 years old with its peak age from 40 to 49, which is 10–15 years earlier than in the US [1]. Unfortunately, because of the late treatment, a part of patients, which is as high as about 35% in China, are ARTICLE IN PRESS www.elsevier.com/locate/jlumin 0022-2313/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jlumin.2005.12.050 Corresponding author. Department of Physics, Surface Physics Laboratory (National Key laboratory), Synchrotron Radiation Research Center, Fudan University, Shanghai 200433, China. Tel.:/fax: +86 21 65643522. E-mail address: xy-zhang@fudan.edu.cn (X. Zhang)
C. Liu et al/ Journal of Luminescence 119-120(2006)132-136 133 already in the middle stage or even the later period 2. Samples and methods of cancer when they begin their therapy To enhance the early detection rate, much n our experiments, the pathological sections of research work has been done in the last years by human normal and diseased breast tissues in using spectroscopic methods [2,3], which are different cancerous stages (i.e. benign and malig mostly based on compact spectrometers focusing nant) are stuck to a CaF2 crystal for standard on UV excitation with the purpose to reach a FTIR analysis. All of the specimens are prepared relative high fluorescence yield. In addition, the in the Pathology Department of the Cancer laser spectroscopy provides a powerful and sensi- Hospital, Medical Center of Fudan University tive approach to reveal changes in the structural under the permission and authorization of the and biochemical properties that occur in health relevant rules in China and abnormal cells in tissues [4]. There are well- The IR spectra were measured by the bomen known intrinsic fluorophores, which are bound to DA-8 FTIR spectrometer with an energy resolu- proteins within cells and fluoresce in visible tion up to 0.004 cm at the ir beamline of ctral region, can display well-defined spectral National Synchrotron Radiation Laboratory features. But it is always difficult to obtain (NSRL), University of Science and Technology properly the quantitative differences in spectral of China. The IR absorption spectrum was characteristics among normal, precancerous and scanned in transmission mode. To eliminate the cancerous tissues from the spectra Georgakoudi et differences due to the nonuniformity of thickness al. [5] pointed out that one of the factors hindering of samples and the varying of intensity of light the extraction of quantitative biochemical infor- source, all spectra were su bsequently calibrated mation from measured tissue fluorescence spectra was the presence of potentially significant distor- tions introduced by tissue scattering and absorp- 3. Results and discussion tion. They have developed a method for extracting the fluorescence spectral features of collagen and The SR-FTIR spectra of normal, benign and NAD(P)H in vivo over a wide range of excitation and emission wavelengths [5]. In recent years, a from 900 to 3600 cm. The absorption peaks are new bio-spectroscopic technique, the Fourier concentrated mostly in three energy ranges. First transform infrared(FTIR) spectroscopy, has been in range of 900-1200 cm the IR absorption is applied to study on biology samples at high spatial mainly due to the cellular constituents of carbohy solutions [6]. This technique enables one to study drate, nucleic acids and the phosphates; then is the the state of chemical bonds and the relative absorption due to proteins in 1400-1750cm and concentrations of lipids, proteins, carbohydrates that in 2700-3600 cm should result from the and phosphorylated molecules, etc. On the other absorption of lipids and N-h amino groups [7I hand, the synchrotron radiation has unique The IR absorption spectra in 900-1200cm-I characteristics in infrared(IR) range compared range are shown in Fig. l(a) and their second ness,excellent collimation and broad continuous Fig. 1(b). As we know that the glycoge ed in with blackbody radiations, such as high bright order derivatives are calculated and displa spectrum. Therefore, it can produce IR spectra kind of important carbohydrates in breast tissue. with higher ratio of signal to noise and better It should make an important contribution to IR spatial resolution than conventional IR spectrum. absorption in this region. Curves I, II and Ill are In this paper, in order to obtain more information corresponding to the absorption due to normal and comprehension of the breast cancer, we have benign and malignant tissues, respectively studied the spectral characteristics of breast Through the second-order derivative of absorption tissues, which are normal or in different cancerous curves, we note that the absorption spectrum of ages by synchrotron radiation based FTIr normal tissue is of more abundant spe (SR-FTIR) spectroscopy features than one of benign tumor tissues, but
already in the middle stage or even the later period of cancer when they begin their therapy. To enhance the early detection rate, much research work has been done in the last years by using spectroscopic methods [2,3], which are mostly based on compact spectrometers focusing on UV excitation with the purpose to reach a relative high fluorescence yield. In addition, the laser spectroscopy provides a powerful and sensitive approach to reveal changes in the structural and biochemical properties that occur in healthy and abnormal cells in tissues [4]. There are wellknown intrinsic fluorophores, which are bound to proteins within cells and fluoresce in visible spectral region, can display well-defined spectral features. But it is always difficult to obtain properly the quantitative differences in spectral characteristics among normal, precancerous and cancerous tissues from the spectra. Georgakoudi et al. [5] pointed out that one of the factors hindering the extraction of quantitative biochemical information from measured tissue fluorescence spectra was the presence of potentially significant distortions introduced by tissue scattering and absorption. They have developed a method for extracting the fluorescence spectral features of collagen and NAD(P)H in vivo over a wide range of excitation and emission wavelengths [5]. In recent years, a new bio-spectroscopic technique, the Fourier transform infrared (FTIR) spectroscopy, has been applied to study on biology samples at high spatial resolutions [6]. This technique enables one to study the state of chemical bonds and the relative concentrations of lipids, proteins, carbohydrates and phosphorylated molecules, etc. On the other hand, the synchrotron radiation has unique characteristics in infrared (IR) range compared with blackbody radiations, such as high brightness, excellent collimation and broad continuous spectrum. Therefore, it can produce IR spectra with higher ratio of signal to noise and better spatial resolution than conventional IR spectrum. In this paper, in order to obtain more information and comprehension of the breast cancer, we have studied the spectral characteristics of breast tissues, which are normal or in different cancerous stages by synchrotron radiation based FTIR (SR–FTIR) spectroscopy. 2. Samples and methods In our experiments, the pathological sections of human normal and diseased breast tissues in different cancerous stages (i.e. benign and malignant) are stuck to a CaF2 crystal for standard FTIR analysis. All of the specimens are prepared in the Pathology Department of the Cancer Hospital, Medical Center of Fudan University under the permission and authorization of the relevant rules in China. The IR spectra were measured by the BomenTM DA-8 FTIR spectrometer with an energy resolution up to 0.004 cm1 at the IR beamline of National Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China. The IR absorption spectrum was scanned in transmission mode. To eliminate the differences due to the nonuniformity of thickness of samples and the varying of intensity of light source, all spectra were subsequently calibrated. 3. Results and discussion The SR–FTIR spectra of normal, benign and malignant breast tissues have been investigated from 900 to 3600 cm1 . The absorption peaks are concentrated mostly in three energy ranges. First, in range of 900–1200 cm1 the IR absorption is mainly due to the cellular constituents of carbohydrate, nucleic acids and the phosphates; then is the absorption due to proteins in 1400–1750 cm1 ; and that in 2700–3600 cm1 should result from the absorption of lipids and N–H amino groups [7]. The IR absorption spectra in 900–1200 cm1 range are shown in Fig. 1(a) and their second order derivatives are calculated and displayed in Fig. 1(b). As we know that the glycogen is one kind of important carbohydrates in breast tissue. It should make an important contribution to IR absorption in this region. Curves I, II and III are corresponding to the absorption due to normal, benign and malignant tissues, respectively. Through the second-order derivative of absorption curves, we note that the absorption spectrum of normal tissue is of more abundant spectral features than one of benign tumor tissues, but ARTICLE IN PRESS C. Liu et al. / Journal of Luminescence 119– 120 (2006) 132–136 133
C. Liu et al./Journal of Luminescence 119-120(2006)132-136 0.8 7 1464cm 4 0.3 0.2 g04 5010001050110011501200 14001450150015501600165017001750 Fig. 2. IR absorption spectra in the amide I and amide Il egions. Curves I. Il and Ill are corresponding to the 0x104 absorption of normal. benign and malignant tissues, respec- 2.0x10-4 83.0x10 and benign tissues. Then, the absorption peak at 84.0x10-4 1500 cm can be observed only in malignant tissue and might result from the C=C vibration 60x10 of 106010801100 1474 cm, whose double peak structure was not Wavenumber(cm") reported before, emerge as shown in Fig. 2 Fig. 1. IR absorption spectra in the drate absorption The IR spectra in the lipid and N-H amino region(a)and their second-order de b). Curves l. ll group absorption regio from 2700 to 3600 cm and Ill represent absorption of norma and malignant are shown in Fig. 3(a). The three main peaks at tissues, respectively 2850.2917 and 2955cm-I are all resulted from the stretching vibrations of the organic groups CH and CH3 of the acyl chains inside fatty acids [9] the spectrum of malignant cancerous tissue is more The calculated second order derivatives are shown complicated. There are two obvious characters in Fig. 3(b). It is easy to see that the IR absorption shown in spectrum of diseased tissues. One is the spectral structures, hence the chemical compo- absorption peaks shift somewhat relative to that of nents, of normal tissue are more abundant than normal tissues, such as the vibration peak of the ones of tumor tissue at 3100-3500 cm region nucleic acid at 1082 cm. Another is that a peak There are more abundant spectral features in the at 968 cm is observed only in benign tissue but absorption spectrum of normal tissue than one of neither in normal nor in malignant ones cancerous tissues through comparing the second Fig 2 shows the absorption spectra of normal order derivatives of absorption curves in 900-1200 (curve I), benign(curve ID) and malignant(curve and 3100-3500cm. These features, which are ID) tissues in 1400-1750 cm region. The peak at related to certain biological activities, could be 1655 cm(corresponding to amide I bond), which used to distinguish normal tissues and diseased can be ascribed to the absorption of the C=o ones and to differentiate benign tumor and stretching vibration coupled to the in-phase malignant cancer. In 900-1200 cm region, the bending of the N-H bond [8], and the peak at enhanced absorption in tumor tissue implies that 1543 cm(corresponding to amide II bond)are the contents of primary components such as the stronger in malignant tissue but weaker in normal polysaccharides and various DNA functional
the spectrum of malignant cancerous tissue is more complicated. There are two obvious characters shown in spectrum of diseased tissues. One is the absorption peaks shift somewhat relative to that of normal tissues, such as the vibration peak of nucleic acid at 1082 cm1 . Another is that a peak at 968 cm1 is observed only in benign tissue but neither in normal nor in malignant ones. Fig. 2 shows the absorption spectra of normal (curve I), benign (curve II) and malignant (curve III) tissues in 1400–1750 cm1 region. The peak at 1655 cm1 (corresponding to amide I bond), which can be ascribed to the absorption of the CQO stretching vibration coupled to the in-phase bending of the N–H bond [8], and the peak at 1543 cm1 (corresponding to amide II bond) are stronger in malignant tissue but weaker in normal and benign tissues. Then, the absorption peak at 1500 cm1 can be observed only in malignant tissue and might result from the CQC vibration of pyrrole. Two absorption peaks at 1464 and 1474 cm1 , whose double peak structure was not reported before, emerge as shown in Fig. 2. The IR spectra in the lipid and N–H amino group absorption region from 2700 to 3600 cm1 are shown in Fig. 3(a). The three main peaks at 2850, 2917 and 2955 cm1 are all resulted from the stretching vibrations of the organic groups CH2 and CH3 of the acyl chains inside fatty acids [9]. The calculated second order derivatives are shown in Fig. 3(b). It is easy to see that the IR absorption spectral structures, hence the chemical components, of normal tissue are more abundant than the ones of tumor tissue at 3100–3500 cm1 region. There are more abundant spectral features in the absorption spectrum of normal tissue than one of cancerous tissues through comparing the secondorder derivatives of absorption curves in 900–1200 and 3100–3500 cm1 . These features, which are related to certain biological activities, could be used to distinguish normal tissues and diseased ones and to differentiate benign tumor and malignant cancer. In 900–1200 cm1 region, the enhanced absorption in tumor tissue implies that the contents of primary components such as the polysaccharides and various DNA functional ARTICLE IN PRESS 900 950 1000 1050 1100 1150 1200 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Absorbance (a.u.) Wavenumber (cm-1) I II III 960 980 1060 1080 1100 0.0 4.0x10-4 3.0x10-4 2.0x10-4 1.0x10-4 -1.0x10-4 -2.0x10-4 -3.0x10-4 -4.0x10-4 -5.0x10-4 -6.0x10-4 Second Order Derivative Wavenumber (cm-1) I II III 968cm-1 1082cm-1 (a) (b) Fig. 1. IR absorption spectra in the carbohydrate absorption region (a) and their second-order derivatives (b). Curves I, II and III represent absorption of normal, benign and malignant tissues, respectively. 1400 1450 1500 1550 1600 1650 1700 1750 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Absorbance (a.u.) Wavenumber (cm-1) I II III 1655cm-1 1543cm-1 1464cm-1 1474cm-1 1500cm-1 Fig. 2. IR absorption spectra in the amide I and amide II regions. Curves I, II and III are corresponding to the absorption of normal, benign and malignant tissues, respectively. 134 C. Liu et al. / Journal of Luminescence 119– 120 (2006) 132–136
C. Liu et al/ Journal of Luminescence 119-120(2006)132-136 1.41280cm B-sheet structural absorptions in malignant tissue but smaller in normal and benign tissues [3]. The double peak at 1464 and 1474 cm can be clearly 巴 1.0 observed in sr-ftir but not in conventional ir experiments, because the resolving power is low in the latter method and the double peak cannot be tissues, the relative high intensity of two reflects the metabolizing is strong in malignant tumor tissues. Cancer cells have a higher meta bo- 2800 3000 3200 3400 3600 lism than normal, healthy cells. The peak of Wavenumber(cm) 1500 cm. which is related to the c=c vibration of pyrrole in red cells, is usually weaker in tissues 1.0x10 and difficult to be observed. This peak exists only in spectrum of malignant tissue. It is probably due to the of red cells in process of vascul genesis in breast tissues during their cancerous progress [11]. It might be an important aura of -5.0×105 reas cancer fact that 3100-3500cm region are not apparent in tumor 1.0X10 and cancer tissues reflects certain kinds of sub structures inside the N-h bond are gradually 1.5x1 damaged in progression to cancer. Wavenumber(cm") Fig. 3. IR absorption spectra in the lipids and N-H bond ption region (a) and their order derivatives (b) 4. Conclusions within 3100-3500cm lipids absorptions and ertain sub-structures relative to H bond are observed Curves I, II and Ill represent abs In summary, by synchrotron radiation based malignant tissues, respectively. FTiR absorption spectra, there are obvious differences of spectral structures among benign and malignant breast tissues. Having analyzed carefully the whole IR absorption groups are increased in the progression to cancer. spectrum in energy range of 900-3600 cm,we The complicated spectrum structures could have a general impression: the Ir absorption understood by the fact that in malignant tissues a spectrum varies from to be featured abundantly to big portion of chemical bonds of proteins is faint from normal breast tissue to benign tumors roken in cancerous progress. The shifts of while it develops from relatively smooth spectrum absorption peaks maybe result from such kind of to much more complicated one in progression to deterioration and the putrescence of tissues as well cancer of the diseased tissue. on the other hand The 968 cm"peak observed only in benign tissues the high resolving power of synchrotron radiation shows the splitting of cells or/ and dNA in growing based FTIR can make closer peaks, such as the process of tumor [10). The peak of 1655 cm is double peak at 1464 and 1474 cm be visible. attributed to the absorption of the C=O stretch- Some specific absorption peaks are found by ing vibration coupled to the in-phase bending of synchrotron radiation based FTI the N-H bond which may represent certain kind of may help us diagnose whether the breast tissue is a helix structure inside [7]. The peak at 1543 cm healthy or diseased, or in which stage of progres may represent that there is larger anti-parallel Sion to cancers
groups are increased in the progression to cancer. The complicated spectrum structures could be understood by the fact that in malignant tissues a big portion of chemical bonds of proteins is broken in cancerous progress. The shifts of absorption peaks maybe result from such kind of deterioration and the putrescence of tissues as well. The 968 cm1 peak observed only in benign tissues shows the splitting of cells or/and DNA in growing process of tumor [10]. The peak of 1655 cm1 is attributed to the absorption of the CQO stretching vibration coupled to the in-phase bending of the N–H bond which may represent certain kind of a helix structure inside [7]. The peak at 1543 cm1 may represent that there is larger anti-parallel b-sheet structural absorptions in malignant tissue but smaller in normal and benign tissues [3]. The double peak at 1464 and 1474 cm1 can be clearly observed in SR–FTIR but not in conventional IR experiments, because the resolving power is low in the latter method and the double peak cannot be resolved. Compare with normal and benign tissues, the relative high intensity of two peaks reflects the metabolizing is strong in malignant tumor tissues. Cancer cells have a higher metabolism than normal, healthy cells. The peak of 1500 cm1 , which is related to the CQC vibration of pyrrole in red cells, is usually weaker in tissues and difficult to be observed. This peak exists only in spectrum of malignant tissue. It is probably due to the increase of red cells in process of vasculogenesis in breast tissues during their cancerous progress [11]. It might be an important aura of breast cancer. The fact that all peaks at 3100–3500 cm1 region are not apparent in tumor and cancer tissues reflects certain kinds of substructures inside the N–H bond are gradually damaged in progression to cancer. 4. Conclusions In summary, by synchrotron radiation based FTIR absorption spectra, there are obvious differences of spectral structures among normal, benign and malignant breast tissues. Having analyzed carefully the whole IR absorption spectrum in energy range of 900–3600 cm1 , we have a general impression: the IR absorption spectrum varies from to be featured abundantly to faint from normal breast tissue to benign tumors; while it develops from relatively smooth spectrum to much more complicated one in progression to cancer of the diseased tissue. On the other hand, the high resolving power of synchrotron radiation based FTIR can make closer peaks, such as the double peak at 1464 and 1474 cm1 be visible. Some specific absorption peaks are found by synchrotron radiation based FTIR method, which may help us diagnose whether the breast tissue is healthy or diseased, or in which stage of progression to cancers. ARTICLE IN PRESS 2800 3000 3200 3400 3600 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Absorbance (a.u.) Wavenumber (cm-1) III II I 2955cm-1 2917cm 2850cm -1 -1 3100 3200 3300 3400 3500 -1.5x10-4 -1.0x10-4 -5.0x10-5 0.0 5.0x10-5 1.0x10-4 Second Order Derivative Wavenumber (cm-1) III II 3282cm-1 3198cm-1 I 3426cm-1 3488cm-1 (a) (b) Fig. 3. IR absorption spectra in the lipids and N–H bond absorption region (a) and their second order derivatives (b) within 3100–3500 cm1 region. Strong lipids absorptions and certain sub-structures relative to the N–H bond are observed. Curves I, II and III represent absorption of normal, benign and malignant tissues, respectively. C. Liu et al. / Journal of Luminescence 119– 120 (2006) 132–136 135
C. Liu et al./Journal of Luminescence 119-120(2006)132-136 Acknowledgments 3R. Eckel, H. Huo, H. Guan, et al., Vibrational Spectro- scopy27(2001)165 This work was supported by National Basic [4]R.R. Alfano. G.C. Tang, A. Pradhan, et al. IEEE Research Program of China(No. 2005CB523306) uant.Elec.23(1987)1806 C. Jacobson. MG One of authors(C. Liu) would like to thank the Cancer Res 62(2002)682. support given by the Synchrotron Radiation Fund [ 6E. Gazi. J. Dwyer, N.P. Lockyer. et aL., Vibrational of Innovation Project of Ministry of Education, Spectrosc. 38(2005)193 China (No. 20041204S, National Synchrotron 7 J.I. Chang, Y B. Huang, P.C. Wu, et al. Gynecol Oncol Radiation Laboratory, University of Science and 91(2003)577 8 H. Fabian, P. Lasch, M. Boese. et al. Biopolymers 67 Technology of China) (2002)354 9S. Mark, R.K. Sahu, K. Kantarovich, et al., J. Biomed. References [ L.G. Benning, V.R. Phoenix, N. Yee, et al., Geochim. Cosmochim. Acta 68(2004)729 地段国量 Peking union1Ummn1 mai, et al.Acad.Radiol.Il ledical College Hospital, 20 June 200 2 M. Romeo, B.R. Wood, M.A. Quinn, et al., Biopolymers 720003)69
Acknowledgments This work was supported by National Basic Research Program of China (No. 2005CB523306). One of authors (C. Liu) would like to thank the support given by the Synchrotron Radiation Fund of Innovation Project of Ministry of Education, China (No. 20041204S, National Synchrotron Radiation Laboratory, University of Science and Technology of China). References [1] Abstract of the workshop on the ‘‘New results of the clinical therapy on the breast cancer’’ in the Peking Union Medical College Hospital, 20 June 2004. [2] M.J. Romeo, B.R. Wood, M.A. Quinn, et al., Biopolymers 72 (2003) 69. [3] R. Eckel, H. Huo, H. Guan, et al., Vibrational Spectroscopy 27 (2001) 165. [4] R.R. Alfano, G.C. Tang, A. Pradhan, et al., IEEE J. Quant. Elec. 23 (1987) 1806. [5] I. Georgakoudi, B.C. Jacobson, M.G. Mu¨ller, et al., Cancer Res. 62 (2002) 682. [6] E. Gazi, J. Dwyer, N.P. Lockyer, et al., Vibrational Spectrosc. 38 (2005) 193. [7] J.I. Chang, Y.B. Huang, P.C. Wu, et al., Gynecol. Oncol. 91 (2003) 577. [8] H. Fabian, P. Lasch, M. Boese, et al., Biopolymers 67 (2002) 354. [9] S. Mark, R.K. Sahu, K. Kantarovich, et al., J. Biomed. Opt. 9 (2004) 558. [10] L.G. Benning, V.R. Phoenix, N. Yee, et al., Geochim. Cosmochim. Acta 68 (2004) 729. [11] R. Tokiya, K. Umetani, S. Imai, et al., Acad. Radiol. 11 (2004) 1039. ARTICLE IN PRESS 136 C. Liu et al. / Journal of Luminescence 119– 120 (2006) 132–136
