光学相干层析成像技术用于裸鼠皮肤霉菌感染研究

利用中心波长为850 nm的宽带光源SLD实现了纵向分辨率为8μm的光学相干层析成像系统。系统采用傅里叶域光学延迟线实现了深度扫描速度为160 mm/s,成像深度为3 mm。获得了裸鼠皮肤霉菌感染部位和健康皮肤的光学相干层析(optical coherence tom ography,OCT)图像,皮肤病变前后的内部结构信息清晰可见。     

生物组织的超声调制光学成像技术

具有超声定位的高空间分辨率和光学检测的高灵敏度的超声调制光学成像技术是一种有前途的无损的生物组织成像技术。文章阐述了该技术的成像原理,评述了前人在散射介质中声光作用机制的理论研究;介绍了该领域在技术路线上的最新研究进展;最后总结了超声调制光学成像技术的优点并展望了其在生物医学领域的应用前景。     

Mechanoluminescence properties of SrAl2O4:Eu2+ phosphor by combustion synthesis

In this paper, europium‐doped strontium aluminate (SrAl₂O₄:Eu²⁺) phosphors were synthesized using a combustion method with urea as a fuel at 600°C. The phase structure, particle size, surface morphology and elemental analysis were studied using X‐ray diffractometry (XRD), transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDX) and Fourier transform infrared (FTIR) spectra. The EDX and FTIR spectra confirm the elements present in the SrAl₂O₄:Eu²⁺ phosphor. The optical properties of SrAl₂O₄:Eu²⁺ phosphors were investigated by photoluminescence (PL) and mechanoluminescence (ML). The excitation and emission spectra showed a broad band with peaks at 337 and 515 nm, respectively. The ML intensities of SrAl₂O₄:Eu²⁺ phosphor increased proportionally with the increase in the height of the mechanical load, which suggests that this phosphor could be used in stress sensors. The CIE colour chromaticity diagram and ML spectra confirm that the SrAl₂O₄:Eu²⁺ phosphor emitted green coloured light. Copyright © 2015 John Wiley & Sons, Ltd.     

The use of intensity‐based Doppler variance method for single vessel response to functional neurovascular activation

This study presents 1 use of optical coherence tomography (OCT) angiography technique to examine neurovascular coupling effect. Repeated B‐scans OCT recording is performed on the rat somatosensory cortex with cranial window preparation while its contralateral forepaw is electrically stimulated to activate the neurons in rest. We use an intensity‐based Doppler variance (IBDV) algorithm mapped cerebral blood vessels in the cortex, and the temporal alteration in blood perfusion during neurovascular activation is analyzed using the proposed IBDV quantitative parameters. By using principal component analysis‐based Fuzzy C Means clustering method, the stimulus‐evoked vasomotion patterns were classified into 3 categories. We found that the response time of small vessels (resting diameter 14.9 ±6.6 μm), middle vessels (resting diameter 21.1 ±7.9 μm) and large vessels (resting diameter 50.7 ±6.5 μm) to achieve 5% change of vascular dilation after stimulation was 1.5, 2 and 5.5 seconds, respectively. Approximately 5% peak change of relative blood flow (RBF) in both small and middle vessels was observed. The large vessels react slowly and their responses nearly 4 seconds delayed, but no significant change in RBF of the large vessels was seen.      

The blocking effect of BmP02, one novel short-chain scorpion peptide on transient outward K(+) channel of adult rat ventricular myocyte

Two components F-2-7-4 and F-2-7-5, each composed of 28 amino acid residues, were purified from the venom of Buthus martensi Karsch by an opportune procedure with cation-exchange column chromatography and repeated HPLC. Both components were totally accounted to about 0.88% dry weight of the crude venom.The molecular weights of both components were determined to be 2950 and 2935 by mass spectrometry, which were fully coincidence with that of the known novel short-chain peptides BmP02 and BmP03, respectively [Romi-Lebrun R, Martin-Eauclaire M-F, Escoubas P, Wu FQ, Lebrun B, Hisada M, Nakajima T. Characterization of four toxins from Buthus martensi scorpion venom, which act on apamin-sensitive Ca²⁺-activated K⁺ channels. Eur J Biochem 1997;145:457–464]. In addition, the sequence of component F-2-7-4 was analyzed to be the same as that of BmP02. The components F-2-7-4 and F-2-7-5 purified in this study were, thus, finally distinguished to be BmP02 and BmP03 from the same venom. Using whole cell patch-clamp recording, it was found that BmP02 diminished the current of transient outward K⁺ channel in adult rat ventricular myocyte in a concentration-dependent manner. The inhibitory effect was reversible. Dynamic studies showed that the activation, inactivation and recovery processes of the transient outward K⁺ channel were not changed significantly after applying of BmP02. In addition, when BmP02 was applied to guinea pig ventricular myocyte, both delayed and inward rectified K⁺ currents showed no change compared with the control. The results suggest strongly that BmP02 or -like peptides from scorpion venom may provide a useful probe for the studying of transient outward K⁺ channel in rat ventricular myocyte.     

金属酞菁光敏剂的三阶非线性光学性能研究

从光动力治疗癌症的疗效着眼研究酞菁配合物的三阶非线性光学性能。用时间分辨简并四波混频方法测量苯硫基钛菁锌(C56H32S4Zn),苯硫基铝酞菁(C56H32AlN8O4)以及烷氧基铝酞菁(C56H32AlN8O4)的三阶非线性光极化率;测量四波混频响应的衰减过程;研究时间响应的超快过程和慢过程及其动力学机制,它们分别对应于单态和三线态的寿命。在荧光显微成像系统中观察三种酞菁光敏剂对人肝癌细胞杀伤的形态变化,并用MTT方法检测细胞存活率。对三种酞菁配合物的三线态量子产率和寿命进行测定,结果与它们对人肝癌细胞的光动力杀伤作用相关联。     

Neuronal Correlates of Spatial Working Memory in the Endbrain of Crows

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动物活体内细胞光操控的研究进展

动物活体环境下单细胞的光操控对于研究细胞的结构和功能,细胞与组织之间的相互作用,以及细胞病变机理、血栓形成机制和肿瘤细胞迁移等生物医学问题具有重要意义。2013年,光镊技术首次应用于活体动物内单细胞的捕获和操控,开辟了活体动物内光学操控新领域。本文就该领域涉及的活体操控技术及近来取得的重要研究进展进行概述,简要分析了实现深度组织内细胞操控所遇到的技术瓶颈并讨论了解决方案。     

新生大鼠下丘脑神经元L-Ca~(2 )通道电流活动特征

目的 :研究新生大鼠下丘脑神经元L Ca2 通道单通道特性 ;Ca2 通道激动剂BayK 86 44对Ca2 通道单通道特性的影响。方法 :采用神经元急性分离技术 ;用膜片钳细胞贴附式记录方式进行研究。结果 :大鼠下丘脑神经元L Ca2 通道是一种电导相对较大的Ca2 通道 ,其电导为 (2 9.5± 3.1)pS ,平均开放时间 (τ0 )为 0 .2 8ms,平均关闭时间的短关闭时间常数 (τc1)为 2 .91ms,长关闭时间常数 (τc2 )为 5 3.2 2ms。此通道几乎不存在时间依赖性失活。BayK86 44显著增加通道的开放概率 ,通道平均开放时间增加为 1.6 1ms。结论 :下丘脑神经元存在L Ca2 通道 ,该通道具有明显电压依赖性 ,而无显著的时间依赖性。通道特征与文献报道的其它神经元上L Ca2 通道相似 ,也有明显不同 ,显示下丘脑神经元L Ca2 钙通道的独特性     

高动态光学血管造影成像

我们提出一种高动态光学血管造影成像(HDOA)方法来实现活体生物样本血管造影成像.该方法通过设置高动态范围曝光时间,依据动态积分效应和吸收效应以实现高动态积分时间调制.通过该方法,不仅能够同时获得各级血管清晰的造影图像,还能消除样品厚度不均、吸收系数不同对成像造成的影响.论文以仿体和活体金鱼为样品,通过实验验证了HDOA方法根据动态积分调制效应和吸收效应,能有效实现各级血管同时成像.