汉语成语结尾字事件相关电位N400的研究

目的 通过记录汉语成语结尾字匹配与不匹配事件相关电位N400的变化，探讨视觉词语认知模式及汉字认知加工特征。方法发采用南方医院研制的事件相关电位仪，对15例21—36岁健康人右利手受试者中，进行汉语成语正常结尾字(匹配字)与歧义字(不匹配字)N400的研究。结果 受试者对结尾词匹配与不匹配组的N400成分在潜伏期及波幅差异有显著性(P≤0．01)，不匹配组的N400波幅高，潜伏期长。N400广泛分布于各区，左侧比右侧波幅偏高。结论 汉语成语结尾字匹配与不匹配的N400与字词认知中的语义密切相关，有一定的临床价值，可用于临床多种伴有语言障碍疾病的评估。     

Auditory and visual semantic priming using different stimulus onset asynchronies: An event-related brain potential study

Semantic priming effects (behavioral and electrophysiological) were compared in the visual and auditory modalities across three stimulus onset asynchronies (SOAs; 0, 200, and 800 ms). When both prime and target were presented in the visual modality (the prime just to the left of a fixation point and the target to the right) there were N400 priming effects present across the three SOAs. However, the N400 in the 0-ms SOA condition extended longer in time (800 vs. 500 ms) than in the other SOAs. When both the prime and target were presented in the auditory modality (the prime to the right ear and the target to the left), the largest priming effects were found for the 800-ms SOA. Moreover, there was a relatively early priming effect present in the 0- and 800-ms SOA conditions but not in the 200-ms condition. The results are discussed in terms of modality differences in the time course of word comprehension processes.     

Use of an in Vitro Model for the Assessment of Muscle Damage from Intramuscular Injections: in Vitro-in Vivo Correlation and Predictability with Mixed Solvent Systems

The potential of binary mixtures of propylene glycol–water, ethanol–water, and polyethylene glycol 400–water to cause skeletal muscle damage (myotoxicity) following intramuscular injection was examined with an in vitro model using the isolated rat muscle. At moderate concentrations (20–40%, v/v) of the organic cosolvent, the order of myotoxicity was propylene glycol > ethanol polyethylene glycol 400. The in vitro results were then compared with in vivo toxicity in rabbits after injection of normal saline, 40% (v/v) polyethylene glycol 400, 40% (v/v) propylene glycol, indocyanine green in normal saline, and indocyanine green in 40% (v/v) propylene glycol. Employing the area under the creatine kinase activity curve from 0 to 72 hr as the index of skeletal muscle damage, an excellent in vitro–in vivo correlation was observed. The basic myotoxicity relationships obtained from the binary cosolvent systems were then used to examine the myotoxicity of ternary organic cosolvent mixtures. Several mixed solvent systems with the same theoretical molar solubilization power for a model compound, diazepam, were selected to determine (1) if myotoxicity can be reduced by changing the composition of the ternary mixtures and (2) if myotoxicity of the individual components is additive. For the solvent systems containing propylene glycol, ethanol, and water, the total myotoxicity equaled the sum of the individual myotoxicity of each component. In contrast, for the solvent systems containing polyethylene glycol 400, the total myotoxicity was only half of the sum of individual toxicities. These results suggest that polyethylene glycol 400 in mixed cosolvent systems might have a protective effect on the myotoxicity generated by intramuscular injections.     

Ultrastructural studies on the localization of IgG in the aortic endothelium and subendothelial intima of atherosclerotic and nonatherosclerotic rabbits

Immunoelectron microscopy with peroxidase-conjugated Fab fragments of anti-IgG was used for studying the localization of IgG in the aortic endothelium and subendothelial intima of atherosclerotic and nonatherosclerotic rabbits. Small amounts of IgG were found in the cell coat, in caveolae and vesicles, and also in intercellular clefts of endothelial cells from normocholesterolemic rabbits. Injured endothelial cells exhibited prominent accumulations of IgG in the cytoplasmic matrix, possibly due to leakage through plasma membrane defects. In atherosclerotic lesions from hypercholesterolemic rabbits, there was a striking increase in the amount of IgG-reactive material in the cell coat and vesicles of intact endothelial cells. Also in these animals, injured endothelial cells were characterized by a cytoplasmic IgG accumulation. There were prominent IgG depositions in the subendothelial zone of the lesions. IgG was adhering to collagen fibers, and also coating the surfaces of subendothelial foam cells. The pathophysiological significance of an interaction between such intimal IgG and phagocytes is discussed.     

P300, N400, aerobic fitness, and maximal aerobic exercise

Electrophysiological effects of aerobic fitness and maximal aerobic exercise were investigated by comparing P300 and N400 before and after a maximal cycling test. Event-related potentials (ERPs) were obtained from 20 students divided into two matched groups defined by their aerobic fitness level (cyclists vs. sedentary subjects). The session of postexercise ERPs was performed immediately after body temperature and heart rate returned to preexercise values. At rest, no significant differences were observed in ERP parameters between cyclists and sedentary subjects. This finding argued against the hypothesis that ERP modifications may be directly assumed by aerobic fitness level. The postexercise session of ERPs showed a significant P300 amplitude increase and a significant P300 latency decrease in all subjects. Similarly, N400 effect increased significantly after the maximal exercise in all subjects. ERP changes were of the same magnitude in the two groups. The present study argues for a general arousing effect of maximal aerobic exercise, independently of the aerobic fitness level.     

熊果酸液固压缩片的制备及优势简

目的优选制备熊果酸液固压缩片的处方并探讨其优势。方法用不同处方制备熊果酸液固压缩片,同时与普通片剂进行片剂质量和溶出度比较。结果液固压缩片较普通片剂的溶出度大幅度提高,在45Min时最多可提高214％;片剂质量在崩解时限、重量差异等方面均明显优于普通片剂,崩解时限至少缩短一半。结论液固压缩技术可应用于难溶性药物熊果酸的制剂,且具有一定优势。     

降胆固醇药物F400的研究——Ⅰ.产生菌的分类、发酵及降胆固醇活性

真菌F400属红曲霉属的一种,称为红曲霉F400。它产生一个降胆固醇的活性物质F400。降胆固醇活性及理化性质的比较研究证明,F400与高效降胆固醇药物Lovastatin(Monacolin K)为相同的物质。     

正常人汉语句子事件相关电位N400的研究

目的研究汉语句子结尾词匹配与不匹配事件相关电位N400的变化,探讨正常人汉语句子N400的特征。方法对15名21~36岁右利手健康受试者,进行汉语正常句子结尾匹配词(匹配)与句子结尾歧义词(不匹配)N400的研究。结果受试者对句子结尾词匹配与不匹配的N400成分在潜伏期及波幅有显著性差异(P<0.05),句子不匹配结尾词的N400潜伏期较长,N400波幅高。N400广泛分布于脑部各区,左侧波幅偏高。结论汉语句子结尾字匹配与不匹配的N400与字词认知中的语义密切相关,可作为一个有临床价值的认知电位而用于临床多种伴有语言障碍疾病的评估。     

软胶囊崩解迟缓现象影响因素研究

目的：研究储存条件以及软胶囊处方对明胶胶片稳定性的影响,探讨软胶囊崩解迟缓的原因。方法：制备明胶胶片模拟软胶囊囊壳,采用溶胀动力学法测定明胶胶片平衡溶胀量(Seq),同时测定软胶囊内容物溶媒PEG400中甲醛含量。以上述结果为指标,考察不同储存条件与胶囊处方对明胶胶片交联程度的影响。结果：空白明胶胶片在40℃条件下Seq与对照组具有极显著性差异,PEG400中甲醛含量增加。含有甘油、山梨醇、二氧化钛等辅料的胶片浸泡在PEG400中后Seq与对照组具有极显著性差异,PEG400中甲醛含量量著增加。加速条件下含有抗氧剂的胶片Seq与PEG400中甲醛含量变化不大。结论：在考察的储存条件中,温度对软胶囊稳定性影响较大。含有一些常用辅料的明胶胶片易受PEG400中外源性醛类杂质的影响,Seq降低。低沮保存、纯化辅料以及添加抗氧剂有助于缓解软胶囊崩解迟缓现象的发生。     

How do taxonomic versus thematic relations impact similarity and difference judgments? An ERP study

Taxonomically related concepts like “bee” and “butterfly” and thematically related concepts like “bee” and “honey” have different roles in similarity judgments. We examined the complex impact of taxonomic and thematic relations on similarity and difference judgments via ERPs in a S1–S2 paradigm. Subjects were required to remember a word denoting some object or animal (S1), and compare that to a second word (S2) that was either thematically related, taxonomically related or unrelated to S1, making a “high” or “low” similarity and difference judgments in separate blocks. We found two main differences that suggest thematic and taxonomic relations engage distinct neural processes. The first difference is an N400 effect peaking between 300 ms and 400 ms that is more negative for unrelated words than for thematically and taxonomically related words. The second difference is a frontally distributed P600 peaking between 500 ms and 600 ms that is larger for taxonomically related words than for both unrelated and thematically related words. These results suggest that the dual process model for perceiving similarity is superior to the comparison only model of similarity judgments, and furthermore, provide evidence that the thematic relations are dissociative from taxonomic relations in making similarity and difference judgments.