Quantitative analysis methods of white matter microstructure based on diffusion tensor imaging and its application in chronic pain research / 生理学报

As the two essential components, the white matter and gray matter compose the central nervous system of the brain. Widely known that axons of neurons mainly form the white matter, and these formed nerve fibers are responsible for transmitting information among various brain regions to achieve the coordinated operation of the entire brain. Early research on the white matter could only be done by dissecting living animals or human cadavers, until Basser et al. proposed diffusion tensor imaging (DTI) technology in 1994, which could detect the diffusion characteristics of water in the brain in vivo noninvasively. Accordingly, this technology could be applied to investigate the diffusion movement of water in white matter to obtain the information of direction and micro-anatomy of white matter fiber bundles. With the advancement on the display and analysis of the anatomical structure of white matter fiber bundles, the exploration of microscopic pathological changes, and the assistance of clinical diagnosis and neurophysiological research, DTI technology has become one of the most popular topics in brain science research. Chronic pain refers to pain lasting more than three months, which not only seriously affects the patient's physical and social functions, but also dramatically reduces the quality of life. It was reported that long-term pain stimulation might cause pathological remodeling of the central nervous system, and abnormalities in white matter were found in imaging examinations of patients with chronic pain. This review introduces the quantitative analysis methods of white matter fiber bundle microstructure based on DTI and its application in chronic pain, and further discusses the application value of DTI technology on clinical research of chronic pain.

Development of Semi-quantitative Solid Sampling Mercury Analyzer for Cosmetics / 分析化学

On the basis of the chromogenic reaction between Hg and CuI, a semi-quantitative solid sampling Hg analyzer comprising the catalytic furance, Hg testing tube, air pump and smart cellphone was developed. White carrier 101 was chosen as the adsorbent for CuI to react with Hg from the catalytic furnace. The established Hg analyzer can not only visually recognize the coloration when Hg exceeding the limit standard, but also semi-quantitatively detect the Hg content in cosmetics fast using a smart cellphone and RGB analysis software, after direct solid sampling introduction of cosmetics sample. The instrumental detection limit ( LOD) of mercury was 50 ng, the linearity ranged from 50 ng to 2500 ng, the linear regression coefficient ( R2) was higher than 0. 97, and the RSD of the corresponding RGB values was 6% ( n=11 ) . Nine real cosmetics samples were measured by the established method, whose relative differences of Hg contents with that by the standard method (Safety Technical Specification for Cosmetics, 2015 edition) were less than 10% . The whole analytical time can be controlled within 5 min. The established instrumental method is simple, fast, accurate and visual, and extremely suitable to fast and on-site monitoring of Hg in cosmetics samples.

Two sets of acupoint combination of similar functions engage shared neural representation: a functional magnetic resonance imaging study / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate whether the neural representations underlying alternating two acupoint combinations (ACs) are the same or not.</p><p><b>METHODS</b>In this functional magnetic resonance imaging study, two sets of analgesia ACs were utilized, including Waiguan (TE5) and Qiuxu (GB40) for Group A, and Neiguan (PC6) and Taichong (LR3) for Group B, which are the most commonly adopted in clinical treatment. Each group had 20 healthy subjects. An experimental design was proposed, which consisted of a pre-needling resting phase, a needling phase and a post-needling resting phase. This paradigm optimally mimics the clinical protocol as well as focuses on both the stimulation and the resting periods. The results were subjected to general linear model analysis, conjunction analysis and the functional connectivity analysis.</p><p><b>RESULTS</b>The rostral anterior cingulated cortex was engaged in the initiative period of the acupuncture effect in both groups, and it was chosen as the seed region for the functional connectivity analysis for the following resting period. The results showed that several shared brain regions were involved in both groups, in particular the insula, amygdala and hypothalamus. Moreover, significant differences were located at the posterior cingulated cortex as revealed by a two sample -test (P<0.05, corrected). Other regions showed no significant differences. This finding was further supported by the spatial correlation analysis that the two groups were significantly correlated (r =0.51, P<0.01).</p><p><b>CONCLUSION</b>This preliminary research helps us understand the neurophysiological mechanisms of acupuncture when following clinical guidelines on ACs, as well as provides an important opportunity to develop better treatment strategies for reducing, or even preventing pain.</p>

Volatile oil of Chinese crude drug against human demodex: Effectiveness and safety / 第二军医大学学报

Objective: To search for effective volatile oil of Chinese crude drug for killing demodex in vitro. Methods: The demodex mites were collected by adhesive cellophane tape technique. The killing effects of different volatile oils against Df and Db were observed by microscope. Normal saline and Xinfu Manling Ointment were used as negative and positive controls, respectively. Skin irritation tests for normal and wounded skin and acute toxicity test were carried out using rabbit skin. Results: The volatile oils of 6 Chinese crude drugs, including clore, orange fruit, manchurian wildginger, cinnamon bark, rhizoma alpinae, and pricklyash peel, were highly potent in killing Df and Db in vitro; and the volatile oil of clore and manchurian wildginger had a better killing effect against Df than Db(P< 0.05). The scores for irritation to normal and wounded rabbit skin were 0.2 and 0.3, respectively, and acute toxicity test showed no obvious toxicity. Conclusion: The volatile oils of the 6 mentioned Chinese crude drugs have satisfactory anti-mite activities in vitro. The volatile oil of clore shows a remarkable activity against demodex in vitro, with good skin safety.