磁共振弥散张量成像的原理及分析

本文介绍了磁共振弥散张量成像的原理及其数据的分析处理方法。在弥散张量成像中，每一体素内水分子的弥散用一个张量进行描述。利用张量的几何性质可对脑白质的细微结构进行定量分析，弥散张量成像可用于对脑白质病变进行定量的分析和诊断。     

血细胞分析仪的工作原理及其近期发展

本文简要介绍了血细胞分析仪的主要工作原理，各主要厂家在血细胞分析仪上采用的白细胞分类技术及业界的技术进展。     

磁共振弥散张量成像的处理和可视化

本文介绍了磁共振弥散张量成像的原理及其数据的分析处理方法.在弥散张量成像中,对每一体素都构造一个张量以描述此体素内水分子的扩散,利用此张量的几何性质可对组织的细微结构进行定量分析.根据弥散张量的对称性,可将其分为三种基本类型以描述弥散椭球的几何特性,由此可求得表征弥散各向异性程度的测度.还可通过伪彩色处理等方法直观的表现弥散张量的几何性质,从而得到脑白质纤维的方向性等信息.本文还介绍了一种白质纤维束的追踪方法及其追踪结果.     

紫贝齿的炮制研究

煅至微红、冷后呈紫棕色的紫贝齿原药及水煎液中钙盐(以CaO计)的含量较煅至红透、冷后呈灰白色的紫贝齿分别增加了10.0%和60.0%,说明紫贝齿煅制时,以煅至微红、冷后呈紫棕色为佳。     

鸡蛋对大鼠胃溃疡的预防作用及其机制初探

目的研究鸡蛋(含蛋壳)对大鼠胃溃疡的影响,机制及其与西药药效的比较。方法以无水乙醇灌胃复制胃溃疡模型,从胃液的pH,胃粘膜溃疡指数和损伤程度三方面观察鸡蛋(含蛋壳)A组,西药B组:西咪替丁 东莨菪碱,空白C组(生理盐水)治疗大鼠消化性溃疡的情况。探讨鸡蛋(含蛋壳)的治疗作用和机制。结果以2ml蛋花汤和0.032g蛋壳粉灌胃4d,2次/d,可明显防止大鼠消化性溃疡的发生,与空白组(pH=2.8333)比较,鸡蛋(含蛋壳)组(pH=6.5833)能降低胃液的酸度(P<0.05);西药组(pH=6.8333)与鸡蛋(含蛋壳)组(pH=6.5833)之间的比较(P<0.05);与空白组(溃疡指数=114.00)比较,鸡蛋(含蛋壳)组(溃疡指数=56.67)能减轻胃粘膜的溃疡程度(P<0.05);粘膜损伤程度:C组>A组>B组。结论蛋花汤中含有的脂肪,蛋白等,尤其卵磷脂可以保护胃粘膜免受胃液中H 的损伤,及其中的还原性成分可以防止胃粘膜受氧自由基的损害,蛋壳含CaCO3可以中和胃液中的H ,对胃粘膜起到保护作用。     

白介素-18等炎性标记物与冠状动脉病变程度的关系研究

目的：探讨炎性标记物白介素-18和白细胞计数在不同程度的冠状动脉病变中的表达情况，以期根据炎性标记物的血浆水平甄别冠状动脉病变的严重程度。方法：测定经冠脉造影确诊的急性冠脉综合征（ACS）病人血浆中白介素-18（IL-18）的含量以及全血白细胞计数，然后比较不同程度冠脉病变组的炎性标记物水平；并比较糖尿病（DM）组和非DM组的差异。结果：白介素-18的含量以及全血白细胞计数在冠状动脉复杂病变组明显高于简单病变组（P〈0．05）。合并有DM的ACS病人白介素-18的含量以及全血中的白细胞计数水平明显高于非DM组（P〈0．05）。结论：在不同程度的冠状动脉病变组和不同危险因素组炎性标记物水平存在着显著性差异。     

Exposure to trichloroethylene and its metabolites causes impairment of sperm fertilizing ability in mice.

Trichloroethylene (TCE) is a prevalent occupational and environmental contaminant that has been reported to cause a variety of toxic effects. Here, we have undertaken studies to test the hypothesis that TCE exposure adversely affects sperm function and fertilization. Sperm retrieved from mice exposed to TCE (1000 ppm) by inhalation for 1 to 6 weeks were incubated in vitro with eggs isolated from superovulated female mice. The number of sperm bound per egg was significantly decreased when mice were exposed to TCE for 2 and 6 weeks but not at exposures of 1 and 4 weeks. In vivo fertilization was also determined in superovulated female mice mated with males exposed to TCE for 2 to 6 weeks. The percentages of eggs fertilized, as assessed by the presence of two pronuclei, were significantly decreased after 2 and 6 weeks of TCE exposure. A slight but insignificant decrease was observed after 4 weeks of TCE exposure. The direct effects of TCE and its metabolites, chloral hydrate (CH) and trichloroethanol (TCOH), on in vitro sperm-egg binding were also investigated. Sperm-egg binding was significantly decreased when sperm were pretreated with CH (0.1-10 microg/mL). Significantly lower levels of sperm-egg binding were also detected with TCOH (0.1-10 microg/mL), although the decreases were not as pronounced as those for CH. These results showed that TCE exposure leads to impairment of sperm fertilizing ability, which may be attributed to TCE metabolites, CH, and TCOH.     

Releasing of The White Paper on Medical Imaging Artificial Intelligence in China

In the afternoon of March 26,2019, The White Paper on Medical Imaging Artificial Intelligence in China was officially released in Beijing by the Chinese Innovative Alliance of Industry, Education, Research and Application of Artificial Intelligence for Medical Imaging (CAIERA). The white paper was co-operatively written by the medical imaging experts from the tertiary Chinese hospitals, the scientific experts from AI research institutions and the leading AI medical enterprises in China. The contents of the white paper not only cover the up-to-date application of AI in medical field, the latest advances of AI algorithms in medical image processing, the data requirement for medical AI development, and the current situation of structured data, but also expatiate the goal and challenge of clinical application for medical imaging AI development in 16 medical subject areas, which helps to identify the demands and opportunities for the AI industry. Forty representative enterprises of AI medical imaging in China were introduced in the white paper. The white paper points out the three key problems in development of AI products: the robustness, ease of usage and data security, which provides guidance of direction and strategy for the enterprises. Particularly, in view of the national policy on developing AI, the white paper gives a profound analysis on the challenges and the opportunities that medical imaging AI is facing. These contents agglomerate the cutting-edge efforts of experts in the industry-academia-research-application chain of medical AI, represent the mainstream voice of the society in China. The White Paper will play a guiding role in understanding the market demands and establishing standardized systems in the path of landing AI products in the field medical imaging. Full text of the White paper is publicly accessible from the CAIERA website, or by scanning the 2D code in the article.     

Intensity and duration of in‐vitro antibacterial activity of different adhesives used in orthodontics

This work investigated the antibacterial activity of 14 bonding agents to predict their ability to inhibit white‐spot development during orthodontic treatment. Standardized, sterilized disks of each material were continuously rinsed (for up to 180 d) in a flow of sterile saline. At predetermined time points, the residual ability of each material to inhibit bacterial growth (determined by measuring the size of inhibition halos around disks placed onto appropriate culture media seeded with Streptococcus gordonii DSM6777, Streptococcus sanguinis DSM20567, Streptococcus mutans DSM20523, or Lactobacillus acidophilus DSM20079) and biofilm formation (determined by measuring the numbers of bacteria adherent to disks following incubation in appropriate broths) was tested in triplicate and compared with the baseline activities of freshly prepared materials. Overall antibacterial and anti‐biofilm activities, adjusted for exposure time and strain of bacteria, were assessed. The decrease of antibacterial activity was faster (30–60 d) and complete for fluoride‐enriched materials, but slower (90 d) and partial for antimicrobial‐containing materials (benzalkonium chloride, zinc oxide, chlorexidine, or MDPB). Materials enriched with benzalkonium chloride, chlorexidine, or MDPB showed the highest antibacterial activities. Anti‐biofilm assays yielded similar results. These data could be helpful for clinicians in the choice of the best performing bonding agent also in light of duration of the clinical application.