Effects of a fractional picosecond 1,064 nm laser for the treatment of dermal and mixed type melasma

Background: Picosecond laser is a novel modality for pigmented skin disorders with extremely short pulse duration. Little is known about the effects of the picosecond laser in melasma. Objective: This study aimed to investigate the efficacy of fractional picosecond 1,064?nm laser in melasma treatment. Study design: A prospective, randomized, assessor-blinded, intra-individual split face comparative study. Methods: Female subjects with melasma were enrolled and received fractional picosecond 1,064?nm laser plus 4% hydroquinone cream on one randomly assigned side of the face; the results were compared to the use of hydroquinone cream only on the contralateral side. The modified melasma area severity index (mMASI) score, melanin index by Mexameter MX18®, participant satisfaction score by quartile rating scale, and the quality of life by the dermatology life quality index (DLQI) were evaluated over 12 weeks. Results: Thirty female subjects completed the protocol. The mean (± standard deviation, SD) mMASI score at the 12-week visit was significantly reduced in the picosecond laser-treated areas compared to controls (3.52 ± 1.4 and 4.18 ± 2.03 respectively; p = 0.035). No differences were observed in the mean Mexameter melanin index, participant satisfaction score, and DLQI score. The observed adverse effects included transient mild erythema and mild skin desquamation. Conclusion: The addition of fractional picosecond 1,064?nm laser to 4% hydroquinone was effective and significantly better than 4% hydroquinone alone for the treatment of melasma.     

超皮秒联合点刺放血疗法治疗黄褐斑的临床疗效观察

目的 探讨Picoway超皮秒联合点刺放血疗法治疗黄褐斑的安全性及有效性.方法 选取2019年1月至2020年1月于本院诊断并治疗的黄褐斑患者80例,按照随机数字表法随机平均分为治疗组和对照组.治疗组采用超皮秒联合点刺放血治疗,对照组采用超皮秒治疗,统计和分析两组患者的疗效、不良反应等情况.结果 治疗组痊愈6例,显效9...     

Intrinsic activity and comparative molecular dynamics of buspirone analogues at the 5-HT(1A) receptors

In CNS, the 5-hydroxytryptamine(1A) (5-HT(1A)) receptors exist in two different populations with different behavioural and physiological effects: (1) somatodendritic autoreceptors located pre-synaptically of 5-HT containing neurons and (2) receptors located post-synaptic to 5-HT containing neurons. Clinical studies have shown that 5-HT(1A) partial agonists have anxiolytic properties, while antagonists of pre-synaptical autoreceptors shorten the onset time of selective serotonin reuptake inhibitors (SSRIs). In the present study, the pre- and post-synaptic activity of structural analogues of buspirone was evaluated in animal models. A three dimensional model of the 5-HT(1A) receptor was used to study their interaction modes and helical displacements upon receptor binding. The predicted receptor-ligand interactions indicated similarities in the receptor binding modes for all buspirone analogues, and no clear relationship between receptor contact residues and activity at pre- and post-synaptic receptors. Comparative molecular dynamics (MD) simulations for 650ps indicated that pre-synaptic antagonistic behaviour is connected to large displacements of transmembrane helix (TMH) 7 upon binding, while pre-synaptic agonistic behaviour is connected to large displacements of TMH2 and small displacements of TMH7. Post-synaptic partial agonist behaviour is connected to large displacements of TMH4 and TMH5 upon binding, while post-synaptic antagonists only slightly displace these helices.     

Picosecond optical breakdown: tissue effects and reduction of collateral damage

The effects of picosecond laser-induced optical breakdown on tissue were investigated using high-intensity 40 ps Nd:YAG laser pulses at 1.06 microns. Tissue damage was evaluated using the corneal endothelium in vitro as a model system. Systematic studies were performed to determine the scaling of the tissue damage and damage range with pulse energy. For suprathreshold lesions, the radius of the damage zone varies as the cube root of the pulse energy, in agreement with simple physical scaling laws. A minimum damage range of less than 100 microns was observed for pulse energies of 8 muJ. Damage morphology was investigated by scanning electron microscopy. Three different damage patterns were observed; cell damage, cell removal, and rupture of Descemet's membrane. Different irradiation geometries were used to study damage mediated by either the shock wave or the cavitation bubble. Comparative studies using 10 ns pulses demonstrated that picosecond pulses yielded a significant reduction in collateral tissue damage.     

黄褐斑的治疗新进展

黄褐斑是一种面部获得性色素增加性皮肤病,多发于东亚地区和肤色较深的个体(FitzpatrickⅢ~Ⅵ型),病因复杂、易复发,治疗困难。目前治疗以有效改善、控制病情为目标,以综合治疗为思路,尚没有单一特效的治疗方法。综合治疗多以防晒、修复皮肤屏障为基础,联合外用药物以及内用氨甲环酸、谷胱甘肽等,中重度可选择化学剥脱或激光、强脉冲光等。但化学剥脱以及美容激光对亚洲肤色人群有色素沉着、色素减退、肤色不均及复发等风险,临床上选择需十分谨慎。     

Adhesive Joints with Laser Shaped Surface Microstructures

One of the most commonly applied methods of joining dissimilar materials is gluing. This could be mainly attributed to the applicability of this technique in various industries. The article presents a method of material surface treatment, which increases the shear strength of adhesive joints for lightweight metals such as aluminum with plastics. For this purpose, laser surface microstructuring was performed on each of the selected construction materials. As a result of the performed treatment, the active surface of the glued area was increased, which increased the adhesive strength. The picosecond laser with UV radiation used in the research is TruMicro 5325c with which material can be removed as a result of the cold ablation phenomenon. The applied parameters of the laser device did not cause thermal damage to the surface of the microstructured materials, which was confirmed by microscopic examination. Laser micromachining did not deteriorate the degree of wetting of the tested materials, either, as was confirmed by the contact angle and surface energy measurements with the use of water as the measuring liquid. In investigated cases of microstructure types, the presented method significantly increased the shear strength of the joints formed, as demonstrated by the presented strength test results. Research has shown that created joints with microstructure made according to the described method, are characterized by a significant increase in strength, up to 376%, compared to materials without microstructure. The presented results are part of a series of tests aimed at selecting the operating laser parameters for the implementation of geometric shapes of microstructures which will increase the strength of adhesive joints in selected materials.