Y. Zhang et al. /Journal of Luminescence 119-120(2006 )96-99 software was used to smooth the raw data and for shows the PL spectra under the excitation of other calculations 457.9 nm, and curves A, B, C, D and E correspond recorded at points A, B, C, D and e, respectively. It can be seen, obviously, that the 3. Results and discussion ratio between intensities of the two sub-bands varies gradually from spectrum A to spectrum E The PL spectra near the center of"Waiqiu'are as shown in Fig 4. Consequently, we could come lown in Fig. 2, in which curves A and B represent to the conclusion that, compared to the porphyr the spectra obtained under the excitation of 457.9 or 488.0 nm, respectively. The emission spectrum corresponding to the excitation of 457.9 nm con- sists of two sub-bands peaked at about 525 and 70000 590nm, respectively, as shown by curve A, while 360000 the 488.0 nm is used as the excitation light: the spectrum is of two sub-bands structure as well, but 50000 the sub-band in the higher energy side is obviously weaker than the other one(see curve b in Fig. 2) The sub-band around 525 nm can be attributed to the fluorescence of flavin adenine dinucleotide FAD)and phospholipids(one kind of lipids). On 3 10000 the other hand, the sub-band peak at about 590 nm might be attributed to the fluorescence of porphyrins, including purine, isoxanthopterin and Our pre-designed sampling points were marked Fig. 3. Photoluminescence spectra of the sample inside the with A. B. C. d and e, as shown in the inset of effective acupuncture area and its outside. Curves A, B. C, D and E are measured from different po Fig. 3. These points are along the direction away upper-right circle Positions A, B, C and D are in the effective from the center of the acupoint to its marginal area of""and e is outside the acupoint rea,and the point e is already outside the effective region of the acupoint. The distance between points A and D is about 2.5 mm. Fig. 3 18 1.6 0.8 2 460480500520540560580600620640660680700720 D(mm) Fig 4. Ratio of the intensity of FAD and Fig. 2. Photoluminescence spectra of""Waiqiu acupoint with lipids to that of porphyrins(R)in different positions A, B, C, D the excitation of (A)457.9 and (B)488.0 nm respectively. and e as a function tance(D)away from point A.software was used to smooth the raw data and for other calculations. 3. Results and discussion The PL spectra near the center of ‘‘Waiqiu’’ are shown in Fig. 2, in which curves A and B represent the spectra obtained under the excitation of 457.9 or 488.0 nm, respectively. The emission spectrum corresponding to the excitation of 457.9 nm con￾sists of two sub-bands peaked at about 525 and 590 nm, respectively, as shown by curve A, while the 488.0 nm is used as the excitation light; the spectrum is of two sub-bands structure as well, but the sub-band in the higher energy side is obviously weaker than the other one (see curve B in Fig. 2). The sub-band around 525 nm can be attributed to the fluorescence of flavin adenine dinucleotide (FAD) and phospholipids (one kind of lipids). On the other hand, the sub-band peak at about 590 nm might be attributed to the fluorescence of porphyrins, including purine, isoxanthopterin and tryptophan [5,6]. Our pre-designed sampling points were marked with A, B, C, D and E, as shown in the inset of Fig. 3. These points are along the direction away from the center of the acupoint to its marginal area, and the point E is already outside the effective region of the acupoint. The distance between points A and D is about 2.5 mm. Fig. 3 shows the PL spectra under the excitation of 457.9 nm, and curves A, B, C, D and E correspond to spectra recorded at points A, B, C, D and E, respectively. It can be seen, obviously, that the ratio between intensities of the two sub-bands varies gradually from spectrum A to spectrum E, as shown in Fig. 4. Consequently, we could come to the conclusion that, compared to the porphyr￾ARTICLE IN PRESS 460 480 500 520 540 560 580 600 620 640 660 680 700 720 2000 4000 6000 8000 10000 12000 14000 16000 Photoluminescence Intensity (a. u.) Wavelength (nm) A B Fig. 2. Photoluminescence spectra of ‘‘Waiqiu’’ acupoint with the excitation of (A) 457.9 and (B) 488.0 nm respectively. 0 10000 20000 30000 40000 50000 60000 70000 450 500 550 600 650 700 E D C B A Photoluminescence Intensity (a. u.) Wavelength (nm) E D C B A Fig. 3. Photoluminescence spectra of the sample inside the effective acupuncture area and its outside. Curves A, B, C, D and E are measured from different positions indicated in the upper-right circle. Positions A, B, C and D are in the effective area of ‘‘Waiqiu’’ and E is outside the acupoint. 0123 5 4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 R (a. u.) D (mm) Fig. 4. Ratio of the emission intensity of FAD and phospho￾lipids to that of porphyrins (R) in different positions A, B, C, D and E as a function of distance (D) away from point A. 98 Y. Zhang et al. / Journal of Luminescence 119– 120 (2006) 96–99