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Archives of plastic surgery. 11/2012; 39(6):675-8.
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ABSTRACT: Epidermal cysts are the most common cysts of the skin. Aconventional epidermal cyst rarely reaches a size of more than 5 cm in diameter. We report on two cases of giant epidermal cyst occurring in the neck. One patient had a cyst measuring 12×9×9 cm and the other patient had a non-pulsatile, dome-shaped lesion in the neck, which measured 6×5×3 cm. The lesions were totally excised. Histopathologically, both were confirmed as giant epidermal cysts.
Annals of Dermatology 09/2011; 23 Suppl 1:S135-8. · 0.53 Impact Factor
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Jang Hyun Lee,
Jai-Kyung Pyon,
Sang Han Lee,
Yoon Jin Lee,
Sang Gue Kang, Chul Han Kim,
Dong Wook Kim,
Hae Seon Nam,
Yoon Hyung Park,
Dong Jun Jeong,
Moon Kyun Cho
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ABSTRACT: TC21 plays an important role in highly aggressive tumor formation, and it was overexpressed in several human cancers, including breast cancer, oral squamous cell carcinoma (SCC), and esophageal SCC. In light of this, we explored the expression of TC21 in overall skin cancers in order to evaluate the relationship between TC21 and malignant skin tumors.
We examined six normal skin tissues and 18 malignant skin tumor tissues, including six malignant melanomas (MM), six SCCs, and six basal cell carcinomas (BCCs) using western blotting for the expression of TC21. In another set, 16 specimens of MM, 16 SCC, and 16 BCC were analyzed for the expression of TC21 using immunohistochemical staining. To evaluate the amount of expression of TC21, the Raytest TINA software was used for western blotting and a histochemical score (HSCORE) was used for immunohistochemical evaluation.
The western blotting and immunohistochemistry showed that TC21 was expressed in all malignant skin tumors and not in normal skin tissues. The relative protein expression was an average of 0.004 in normal skin, 1.042 in MM, 0.621 in SCC, and 0.485 in BCC. In immunohistochemistry, HSCORE for normal skin was an average of 0.05, MM was 2.42, SCC was 2.11, and BCC was 1.22.
This article is the first study demonstrating expression of TC21 in human skin malignant tumors and suggests that TC21 is more expressed in highly aggressive skin tumors.
International journal of dermatology 08/2011; 50(8):956-60. · 1.18 Impact Factor
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ABSTRACT: We investigated the effects of mesenchymal stem cells (MSCs) on wound healing using a three-dimensional (3D) collagen gel scaffold. Three circular full-thickness skin defects were created on the back of Sprague-Dawley rats. One site was covered with a 3D collagen gel containing 2 × 10(6) MSCs (MSCs+/3D collagen+). Another site was replaced with a 3D collagen gel without MSCs and the third site was left empty. The wound size was significantly reduced in the MSCs+/3D collagen+ sites. MSCs+/3D collagen+ sites exhibited the most neovascularization. FISH showed that Y-chromosome possessing cells were found within the dermis of MSCs+/3D collagen+ sites. Gelatin zymography revealed that the most intense expression of MMP-9 was detected early in the MSCs+/3D collagen+ sites. Our results indicate that MSCs upregulate the early expression of MMP-9 which induces the early mobilization of VEGF. Thus, MSCs appear to accelerate significantly wound healing via early activation of MMP-9 and VEGF.
Journal of Korean medical science 06/2011; 26(6):726-33. · 0.84 Impact Factor
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Chul Han Kim
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ABSTRACT: We investigated the effects of various noises on the performance of extended-reach WDM-PONs based on broadband light sources (BLSs). The maximum reach in BLS based WDM-PONs was analyzed by taking into account the impact of relative intensity noise of optical source, chromatic dispersion of transmission fiber and in-band crosstalk. We confirmed that the system's performance of BLS based WDM-PONs would be strongly dependent on the equivalent optical bandwidth of optical source. From the results, we found that the maximum reach in BLS based WDM-PONs operating at 1.25 Gb/s could be increased to be approximately 70 km of single-mode fiber as long as the chirp and relative intensity noise (RIN) of optical source would be suppressed properly.
Optics Express 05/2010; 18(10):9859-64. · 3.59 Impact Factor
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Jang Hyun Lee,
Jae-Kyung Pyon,
Dong Wook Kim,
Sang Han Lee,
Hae Seon Nam, Chul Han Kim,
Sang Gue Kang,
Yoon Jin Lee,
Mi Youn Park,
Dong Jun Jeong,
Moon Kyun Cho
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ABSTRACT: Src family kinases (SFKs) play an important role in cancer proliferation, survival, motility, invasiveness, metastasis, and angiogenesis. Among the SFKs, c-Src and c-Yes are particularly over-expressed or hyper-activated in many human epithelial cancers. However, only a few studies have attempted to define the expression and role of c-Src and c-Yes in cutaneous carcinomas.
To investigate the expression of c-Src and c-Yes in cutaneous carcinomas to include malignant melanoma (MM), squamous cell carcinoma (SCC) and basal cell carcinoma (BCC).
We examined 6 normal skin tissues and 18 malignant skin tumor tissues using western blotting for the expression of c-Src and c-Yes. In another set, 16 specimens of MM, 16 SCCs and 16 BCCs were analyzed for the expression of c-Src and c-Yes using immunohistochemical staining.
Western blotting showed that c-Src was expressed in all malignant skin tumors, but not in normal skin, while c-Yes was expressed in MM and SCC, but not in BCC and normal skin. Immunohistochemical staining results of c-Src and c-Yes in MM, SCC, and BCC mirrored those of the western blot analysis.
c-Src, rather than c-Yes, plays a key role in the proliferation and progression of malignant skin cancers.
Journal of Experimental & Clinical Cancer Research 01/2010; 29:116. · 2.15 Impact Factor
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ABSTRACT: We investigated the impact of in-band crosstalk on the system's performance in wavelength-locked Fabry-Perot laser-diode (FP-LD)-based wavelength-division-multiplexed passive optical networks (WDM PONs). As expected, wavelength-locked FP-LD, which was injected by using an incoherent broadband light source, was more tolerant to in-band crosstalk than distributed-feedback (DFB) laser diode. A 1-dB power penalty in the wavelength-locked FP-LD-based PON system was observed when the crosstalk-to-signal ratio was ~-9 dB. We also compared the measured power penalties with the calculated power penalties. It has been shown that the in-band crosstalk-induced power penalty in wavelength-locked FP-LD-based WDM PON could be estimated properly by taking into account both effects of power addition and signal-crosstalk beat noise.
IEEE Photonics Technology Letters 06/2009; · 2.19 Impact Factor
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ABSTRACT: We have evaluated the performance of strain-chirped fiber Bragg grating for the tunable dispersion compensation in a 40 Gb/s transmission link. Our compensator is well suited for the dispersion trimming in a high-speed transmission system.
Opto-Electronics and Communications Conference, 2008 and the 2008 Australian Conference on Optical Fibre Technology. OECC/ACOFT 2008. Joint conference of the; 08/2008
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ABSTRACT: We propose and experimentally demonstrate a novel bidirectional wavelength-division-multiplexed passive optical network architecture that fully utilizes the superior optical properties of an incoherent continuous-wave (CW) supercontinuum (SC) source. The proposed architecture, which incorporates low-cost Fabry-Perot laser diodes that have been wavelength locked by spectrum-sliced beams from a depolarized 130-nm-bandwidth CW SC source, is based on a unique wavelength band allocation scheme of the C-band for an optical line terminal (OLT), the L-band for optical network units (ONUs), and the U-band for channel monitoring. A cost-effective network that features a single broadband source at the OLT, and no additional wavelength- band-selective monitoring beam reflector at each ONU can be readily achieved. The experimental demonstration presented in this paper is carried out at a data rate of 622 Mb/s over a 25-km standard single-mode fiber.
Journal of Lightwave Technology 11/2007; · 2.78 Impact Factor
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ABSTRACT: We analyze the performance of bidirectional WDM PON architecture which utilizes distributed Raman amplification and pump recycling technique. The maximum reach at data rates of 622 Mb/s and 1.25 Gb/s in the proposed WDM PON architecture is calculated by taking into account the effects of power budget, chromatic dispersion of transmission fiber, and Raman amplification-induced noises with a given amount of Raman pump power. From the result, the maximum reach for 622 Mb/s and 1.25 Gb/s signal transmission is calculated to be 65 km and 60 km with a Raman pump power of 700 mW, respectively. We also find that the calculated results agree well with the experimental results which were reported previously.
Optics Express 11/2007; 15(22):14942-7. · 3.59 Impact Factor
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ABSTRACT: We experimentally demonstrate a long reach (60km), bidirectional, colorless WDM-PON architecture based on uncooled, TO-can packaged RSOAs for upstream and FP-LDs for downstream, which are wavelengthlocked by a spectrum-sliced, high power, depolarised CW supercontinuum injection source.
Optical Communication (ECOC), 2007 33rd European Conference and Ehxibition of; 10/2007
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ABSTRACT: We have experimentally investigated the impact of codirectional Raman gains on the performance of distributed fiber Raman amplified systems. The effects of various noise sources, such as optical signal-to-noise ratio (OSNR) degradation, fiber nonlinearities and surviving channel gain variation in different Raman pumping schemes, were evaluated as a function of input power into a fiber span. For measurements, distributed Raman gain was generated by pumping the fiber span with different combinations of Raman pump power between co- and counterdirections. From the results, we found that a large counterdirectional Raman gain assisted by a small codirectional gain could improve the overall static and dynamic performance of distributed Raman amplified systems.
Optics Express 06/2007; 15(10):6146-51. · 3.59 Impact Factor
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ABSTRACT: We experimentally and analytically compare the performance of directly-modulated, wavelength-locked Fabry-Perot laser diode and EAM-modulated, spectrum-si iced ASE source for wavelength-division multiplexed passive optical network applications. The performance comparison is carried out in terms of intensity noise and dispersion at a data rate of 1.25 Gb/s over a conventional single-mode fiber links.
Optical Fiber Communication and the National Fiber Optic Engineers Conference, 2007. OFC/NFOEC 2007. Conference on; 04/2007
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ABSTRACT: We propose a novel wavelength division multiplexed (WDM) passive optical network (PON) architecture based on the distributed Raman amplification and pump recycling techniques, which features fully bidirectional transmission, relaxed signal power margin, and active light source-free, colorless subscriber units. The reuse of non-negligible residual Raman pump power as a pump for an erbium fiber-based upstream broadband ASE source allows for fully-centralized control of light sources at optical network units (ONUs), while distributed Raman amplification over a transmission link enables us to obtain lossless low power signal transmission. Furthermore, low-cost and colorless ONUs can be realized by use of the Raman pump-recycled erbium ASE and polarization-insensitive electroabsorption modulators. Error-free upstream transmission over a 50 km fiber link is successfully achieved at a data rate of 622 Mbit/s.
Optics Express 11/2006; 14(20):9036-41. · 3.59 Impact Factor
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ABSTRACT: We experimentally demonstrate a WDM PON upstream transmission system using our proposed, depolarised, high power (~500 mW), CW supercontinuum with a spectral bandwidth of ~130 nm as an injection source for Fabry-Pérot laser diodes. Using the system error-free 25 km transmission is achieved at 1.25 Gbit/s.
Optical Communications, 2006. ECOC 2006. European Conference on; 10/2006
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Chul Han Kim
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ABSTRACT: We review the impact of two noises, reflection-induced multi-path interference and pump-intensity noise, on the Raman amplified system's performance. We find that a high reflection could enhance the pump-signal crosstalk in a counter-pumped Raman amplifier.
Optical Internet and Next Generation Network, 2006. COIN-NGNCON 2006. The Joint International Conference on; 08/2006
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ABSTRACT: We experimentally demonstrate a 320 Gbit/s (32Chs times 10 Gibt/s) WDM signal transmission of bending insensitive holey fibers of less than 0.04 dB. Error free operation is achieved for all 32 channels.
Lasers and Electro-Optics, 2006 and 2006 Quantum Electronics and Laser Science Conference. CLEO/QELS 2006. Conference on; 06/2006
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Chul Han Kim
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ABSTRACT: We have analyzed the combined effect of pump-intensity noise and reflections on the performance of counter-pumped Raman amplified systems. The required level of pump-intensity noise was evaluated for negligible enhancement of multi-path interference (MPI). We have also investigated the enhancement of pump-to-signal crosstalk caused by the reflections occurring within transmission fiber. We found that a high reflection (larger than -20 dB) within effective length of fiber could increase the effect of pump-to-signal crosstalk even for the counter-pumped Raman amplifiers.
Optics Express 09/2005; 13(16):6099-104. · 3.59 Impact Factor
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ABSTRACT: We investigate the benefits of using our proposed continuous-wave supercontinuum (CW SC) as a broadband wavelength-locking source for the implementation of extended-reach, colorless, wavelength division-multiplexed passive optical networks (WDM-PONs). More specifically, first, an extended reach WDM-PON architecture based on both the CW SC and our devised C-/L-band beam combiner is proposed, in which the optical line terminal (OLT) is based on Fabry–Pérot laser diodes (FP-LDs), whereas the optical network units (ONUs) are reflective semiconductor optical amplifiers (RSOAs). Second, a theoretical investigation on the maximum reach achievable with the proposed architecture is carried out considering Rayleigh backscattering noise and injection power limits. Only upstream signal performance is compared for the following four cases: (1) superluminescent diode (SLD) broadband source and FP-LD ONU, (2) SLD and RSOA, (3) CW SC and FP-LD, and (4) CW SC and RSOA. The combination of a CW SC injection source and RSOA-based ONUs is found to allow for the longest distance coverage. Finally, the feasibility of the proposed architecture is experimentally analyzed over a 60-km transmission fiber at 622 Mbit/s.
Optical Fiber Technology.
