传统荧光显微成像技术以荧光强度为成像对比度,在获取生物分子位置和浓度信息中具有重要作用,为分子层面的生物医学研究提供了成像工具。而偏振作为荧光的另一重要特性,可以在另一维度提供分子的方向和结构信息,已被广泛应用于荧光偏振显微成像技术中。除此之外,荧光偏振调制也可以通过增强荧光图像稀疏性进而增强图像对比度来获取超分辨尺度的生物分子的位置和方向信息。从物理基础、技术原理、基本实现装置和生物应用等方面,总结了基于荧光偏振特性的不同荧光偏振调制成像技术在分子方向结构成像、超分辨显微成像以及二者的结合方面的发展概况,并对该技术未来的发展方向进行了展望。

不同的生物样本和切片,在进行拉曼探测时,会因为聚焦位置的差异及系统自身的原因导致同一光谱多次检测得到的信号强度不同,难以作定量分析。因此,需要找到一种可行性强的内标或外标的方法,从而有利于比较分析不同强度的拉曼带,实现定量检测。本文以犬类髋关节软骨切片为例,在偏振与非偏振情况下,研究标准正态变换(SNV)及多元散射校正(MSC)等常用方法对拉曼光谱的处理效果,并探究伊红染色剂(Eosin)作为一种新的内标的实际使用效果。结果发现:在非偏振条件下,MSC处理效果更理想；在偏振条件下,以伊红的特征峰1501 cm-1作为拉曼内标效果更理想。本研究证明了伊红的拉曼光谱不具有各向异性,有利于实现生物组织偏振拉曼光谱测量的归一化,且操作简单,结果更可靠。本文的结果为生物样本的拉曼光谱定量分析提供了一种可行的新方法。

在生物医学领域,拉曼光谱学越来越多地应用于目标样本或组织的在体原位无损探测。拉曼探头作为重要的拉曼检测部件,正朝着多样化和功能化方向发展。拉曼信号本身极其微弱,且易被其他噪声信号干扰,因此拉曼探头的设计生产要求极高。对现有拉曼探头的设计及构造进行了深入介绍,包括光纤选择、探头顶端设计、过滤膜/片添加和探头后端优化等;综述了拉曼探头技术在生物医学领域的拓展和应用。其中,拉曼与其他光谱或成像模式结合的探头应用,给生物医学及临床探测等领域带来了新的活力和广阔的应用前景。

为提高偏振荧光图像序列的获取速度,提出利用电光调制器对激发光的偏振方向进行控制并配合相机记录偏振荧光图像的高速偏振荧光显微系统。对激发光路的偏振畸变进行测量和有效补偿,以确保样本平面激发光偏振方向的精确控制。利用巨型单层囊泡样本对实验系统进行测试,结果表明该系统能够以近视频帧率对分子方向信息进行成像,具备监测动态样本分子方向信息的能力。

The stereo vision results from the interaction between geometrical optics and visual psychology. Large depth will bring discomforts for the results of ghosting and flicker. The relevance of the ratio of jumping out depth (RJD) and electroencephalogram (EEG) gravity frequency (GF) was explored to reflect human health under different three-dimensional (3D) depth information (mainly the negative disparity) displayed on a three-dimensional television (3D-TV) with shutter glasses. EEG was obtained from 10 volunteers when they were watching 3D film segments with different negative disparities. The brain GF map shows that the depth information has a stronger influence on the frontal lobe than on the occipital lobe. For regression analysis, nonlinear curve fittings of GF to RJD in Fp1, F3, O2 and T5 channels were mainly performed when RJD ranged from 0 to 3.4, while linear fittings were performed in some special RJD ranges. It also confirms that RJD above 2.2 may lead to discomfort to human body. Finally, it suggests a suitable RJD range for people to watch from the objective method. The outcomes can be used as a guidance to decrease human discomforts induced by 3D production.

Magnetic nanoparticle plays an important role in biomedical engineering, especially in tumor therapy. In this paper, a new technique has been developed by using the rapid moving magnetic nanoparticle under a low-frequency alternating magnetic field (LFAMF) to kill tumor cells. The LFAMF system which was used to drive magnetic nanoparticles (MNPs) was setup with the magnetic field frequency and power range at ~10–100 Hz and ~10–200mT, respectively. During the experiment, the LFAMF was adjusted at different frequencies and power levels. The experimental results show that the liver tumor cells (HepG2) mixed with MNPs (10 μg/mL) became partial fragments when exposed in the LFAMF with different frequencies (~10–100 Hz) and power (~10–200 mT), and the higher the frequency or the power, the more the tumor cells were killed at the same magnetic nanoparticle concentration. Conclusion: Tumor cells were effectively damaged by MNPs under LFAMF, which suggests that they had great potential to be applied in tumor therapy.

Fourier transform infrared imaging (FTIRI) was used to examine the depth-dependent content variations of macromolecular components, collagen and proteoglycan (PG), in osteoarthritic and healthy cartilages. Dried 6 μm thick sections of canine knee cartilages were imaged at 6.25 μm pixel-size in FTIRI. By analyzing the infrared (IR) images and spectra, the depth dependence of characteristic band (sugar) intensity of PG show obvious difference between the cartilage sections of (OA) and health. The result confirms that PG content decreases in the osteoarthritic cartilage. However, no clear change occurs to collagen, suggesting that the OA influences little on the collagen content at early stage of OA. This observation will be helpful to further understand PG loss associated with pathological conditions in OA, and demonstrates that FTIRI has the potential to become an important analytical tool to identify early clinical signs of tissue degradation, such as PG loss even collagen disruption.