目前，辅助激光临床治疗鲜红斑痣所使用的R134a制冷剂喷雾冷却冷量不足，导致表皮黑色素含量高的患者的治疗效果较差。R404A以其更强的冷却能力具有取代R134a的潜力。本文通过实验定量研究了喷雾距离和时间对R404A喷雾冷却类皮肤表面动态传热的影响，并分析了不同工况下传热规律的相似性。结果表明：增加喷雾时间，可以延长对表皮的冷却保护时间；喷雾距离对表面温度的影响取决于时间尺度，短时间喷雾(20 ms)下，表面最低温度T_min随着喷雾距离的增大而升高，而长时间喷雾下(100 ms)，表面最低温度T_min在喷雾距离为30 mm时达到最小值；表面的最大热流密度q_max和最大换热系数h_max随喷雾距离增大而单调递减，与喷雾时长无关。通过理论分析提出了无量纲热流密度随无量纲时间变化的关系式。本研究结果对R404A喷雾冷却未来的临床应用具有重要的指导意义。

近年来,5-氨基酮戊酸(5-aminolevulinic acid, ALA)介导的光动力学疗法(photodynamic therapy, PDT) 已经广泛用于尖锐湿疣、人乳头瘤病毒(human papilloma virus, HPV)感染性皮肤病、非黑素瘤型皮肤癌及癌前病变、中重度痤疮、皮肤光老化等多种皮肤疾病, 并且取得良好疗效, 有安全性、低复发性、选择性、有效性、可重复性、灵活实用性、微创性等优点。ALA-PDT在光敏剂、光源的改进、优化治疗参数的促进下, 在皮肤科领域有很大的应用前景。现在将近年国内外ALA光动力学疗法在皮肤病中的研究及临床应用进展, 进行分析和总结, 为临床医生的合理使用及治疗的选择上提供依据。

Photodynamic therapy (PDT) has poor therapeutic outcomes for the treatment of port-wine stain (PWS) lesions with long drug-light intervals (DLIs). This letter investigates the possibility of improving the treatment efficacy through increasing the laser power density using a computer simulation and a cock comb model. The computational model includes a Monte Carlo simulation for the laser distribution and a calculation of the singlet oxygen concentrations (1O2). Both simulation and experimental results show that increasing the power density from 100 to 140 mW/cm2 not only improves the PDT efficacy, but also results in the unwanted skin damage.

共聚焦激光扫描显微镜作为一种新型的非侵入性图像分析仪器已逐渐成为皮肤疾病诊断、鉴别诊断、随访与动态观察的新方法, 为皮肤科学的发展开辟了广阔前景, 促进了皮肤病学的医学研究与临床治疗。

Two-photon excitation fluorescence (TPEF) and second-harmonic generation (SHG) are detected through multiphoton microscopy (MPM). The major signals have the potential to monitor the process of tissue changes. TPEF and SHG are used to monitor the skin photo-thermal response to irradiation with intense pulsed light sources (\lambda is in the range of 560?1200 nm) and trace the process of skin remodeling in vivo at different time intervals. TPEF intensity is nearly unchanged at different time intervals after irradiation, whereas SHG intensity changes considerably. The results reveal the photo-thermal effect of nonablative light sources and the process of collagen remodeling at the sub-micron level.

Light dose plays an important role in the non-ablative photorejuvenation based on the theory of selective photothermolysis. However, present techniques for determining the light dose in clinical practice are still not accurate enough. We present a new system which monitors the skin tissue response during the laser irradiation in photorejuvenation by measuring the change of the total attenuation coefficient. We also investigate the relationship between the total attenuation coefficient and the energy density, pulse duration, and pulse repetition. In this procedure, the total attenuation coefficient decreases when the light dose increases and the reduction dependes on the light dose. These experimental results indicate that the new system would be a potential tool for accurate light dose determination.

To study characteristics of acoustic wave generated by Q-switched laser on dermal pigmented lesions, pieces of derma peeled from a cavy's body are plucked their hair. The pieces of derma are radiated by Q-switched laser with different energy intensities. Momentary signals of acoustic wave generated by the Q-switched pulsed laser on dermal pieces are detected isochronously with sensors connected to a multi-channel digital oscilloscope. The signal data are analyzed with a personal computor. Clear signal curves of acoustic waves are obtained in the experiment. The amplitudes of the signals present the positive correlation with the energy intensity of the single pulse laser. The acoustic wave signals have practical meanings of reference to the real-time control of laser energy intensity in the course of the therapy of Q-switched laser on dermal pigmented lesions.

目的:探讨Ho:YAG激光在治疗皮肤科疾病中的应用及其优越性.方法:采用 Ho:YAG激光以热凝固效应或气化消融效应治疗1640例皮肤科疾病.峰值能量0.5～1.0J/脉冲,脉冲频率5～15Hz,平均功率2.5～15W.结果:1640例皮肤科疾病均一次治愈.蜘蛛痣、血管角皮瘤、睑黄瘤愈后不留疤痕;尖锐湿疣术后复发或再生者可重复给予治疗,患者术后无疤痕形成、尿道口狭窄等并发症出现;化脓性肉芽肿愈后疤痕无或极小;疣状痣、皮脂腺痣、脂溢性角化、睑缘、鼻腔和外耳道丝状疣、寻常疣、皮赘愈后不留疤痕或留浅疤.结论:采用Ho:YAG激光治疗某些皮肤科疾病,操作简便,定位准确,止血效果好,对周围组织损伤轻微,创面愈合快.比目前常用于皮肤科疾病治疗的CO2激光或Nd:YAG激光疗效更佳.