吴茱萸次碱对小鼠溃疡性肠炎的治疗作用

目的:观察吴茱萸次碱治疗小鼠急性结肠炎的药效及对豚鼠肠道平滑肌运动的影响。方法:2,4-二硝基氯苯(DNCB)／乙醇灌肠制作小鼠急性结肠炎模型,经口给予吴茱萸次碱10、30、100 mg·kg-1,观察吴茱萸次碱对小鼠腹泻,组织形态损伤,结肠组织PGE2含量、MPO活力以及对乙酰胆碱、组胺作用下豚鼠离体肠管收缩运动的影响。结果:DNCB诱发结肠炎后,小鼠出现腹泻、充血、溃疡、肠壁增厚等变化。经口给予吴茱萸次碱后,可以显著改善小鼠的腹泻、组织损伤,并且能够降低结肠组织中MPO活性和PGE2的含量,对乙酰胆碱及组胺作用下豚鼠离体肠管收缩亦表现出显著的对抗作用。结论:吴茱萸次碱可以抑制炎性浸润、渗出和组织增生,减轻结肠黏膜的病理损害和抑制肠道平滑肌运动,对实验性动物急性结肠炎有较好的治疗作用。     

后巩膜收缩术治疗病理性近视黄斑劈裂

目的：评估后巩膜收缩术对病理性近视黄斑劈裂的治疗效果。方法：回顾性研究。选取2014年12月 至2017年04月在南京市第一医院眼科行后巩膜收缩术的病理性近视黄斑劈裂患者24例（45眼）,观察手术前后患者的最佳矫正视力、眼轴长度、屈光度、黄斑区视网膜劈裂高度的状况与手术并发症。对相关计量资料进行重复测量方差分析。结果：患者术前,术后1个月、3个月、6个月及12个月的黄斑区视网膜劈裂高度分别为（494±31）、（299±24）、（256±24）、（200±22）、（168±25）μm,术后各时间点与术前比较差异有统计学意义（均P<0.05）。患者术后1、3、6个月眼轴长度分别为（28.6±2.1）、（28.9±2.0）、（29.3±2.0）mm,与术前[（30.5±2.2）mm]相比差异有统计学意义（P<0.05）,术后12个月眼轴（29.8±2.1）mm,与术前相比差异无统计学意义（P>0.05）。患者术后1个月、3个月的屈光度分别为（-15.14±5.16）D、（-15.64±5.05）D,与术前[（-17.33±7.43）D]相比差异有统计学意义（P=0.013、0.048）,术后6、12个月的屈光度分别为（-15.96±4.97）D、（-17.05±5.10）D,与术前相比差异无统计学意义（P>0.05）。患者最佳矫正视力差异无统计学意义（P>0.05）。结论：针对病理性近视黄斑劈裂伴或不伴视网膜脱离的治疗,后巩膜收缩术的安全性和可行性较好。     

Electromechanical coupling and regulation of force of cardiac contraction

Cardiac muscle fibres, like skeletal muscle fibres, are divided into sarcomeres, the basic unit of contraction. The contractile elements include actin, myosin, tropomyosin and troponin. The myosin molecules are arranged into thick filaments, while the actin molecules form the basis of the thin filaments. The troponin and tropomyosin are attached to the thin filaments as in skeletal muscle. In contrast to fast skeletal muscle fibres, which need to produce repetitive mechanical action only for short periods before resting, and hence can accrue an oxygen debt, cardiac muscle fibres need to perform repetitive activity for long periods (a lifetime) without rest. Consequently, cardiac muscle fibres are much more dependent on the utilization of oxygen and have an abundance of mitochondria, with rapid oxidation of substrates and formation of adenosine triphosphate, needed for mechanical contraction.     

Comparative study of wavelet denoising in myoelectric control applications

Here, the wavelet analysis has been investigated to improve the quality of myoelectric signal before use in prosthetic design. Effective Surface Electromyogram (SEMG) signals were estimated by first decomposing the obtained signal using wavelet transform and then analysing the decomposed coefficients by threshold methods. With the appropriate choice of wavelet, it is possible to reduce interference noise effectively in the SEMG signal. However, the most effective wavelet for SEMG denoising is chosen by calculating the root mean square value and signal power values. The combined results of root mean square value and signal power shows that wavelet db4 performs the best denoising among the wavelets. Furthermore, time domain and frequency domain methods were applied for SEMG signal analysis to investigate the effect of muscle-force contraction on the signal. It was found that, during sustained contractions, the mean frequency (MNF) and median frequency (MDF) increase as muscle force levels increase.     

形态心电图标准在鉴别心室流出道室性心律失常中的价值

目的探讨形态心电图标准在心室流出道（VOT）室性心律失常（VA）中的鉴别价值。方法回顾性分析155例成功行射频导管消融治疗（以下简称消融治疗），并经三维标测或X线影像证实起源于左心流出道（LVOT）室性期前收缩/室性心动过速（PVC/VT）的心电图资料进行观察（观察组），使用系统抽样法选取同期成功行消融治疗的155例右心室流出道（RVOT）起源的PVC/VT进行对照（对照组），再根据起源的位置不同将观察组分为3个亚组：左冠窦（LCS）组、右冠窦（RCS）组、左冠窦下（ILCS）组。观察各组V1、V2导联R波振幅及时限比值、胸导联移行指数、V2导联移行比、胸导联QRS波的移行情况，分析其对LVOT和RVOT及各亚组的PVC/VT鉴别价值，并计算各项指标的灵敏度、特异度、阳性预测值和阴性预测值。结果LVOT和RVOT的PVC/VT的V1、V2导联R波振幅以及R波时限比值及V2导联移行比、胸导联移行、胸前导联移行指数均有较为明显的差异。LVOT亚组分析显示：（1）符合胸导联移行指数＜0，在LCS组、ILCS组及RCS组分别为92.39%（85/92）、90.91%（30/33）、90.00%（27/30）。（2）符合V1导联的R波振幅比值≥0.3及时限比值≥0.5，在上述3组分别89.13%（82/92）、93.94%（31/33）、76.67%（23/30）。（3）符合V2导联的R波振幅比值≥0.3及时限比值≥0.5，在上述3组分别为88.04%（81/92）、93.94%（31/33）、90.00%（27/30）。（4）V2导联移行比＞0.6，在上述3组分别为89.13%（82/92）、93.94%（31/33）、83.33%（25/30）。（5）PVC的胸导联移行在ILCS组有93.39%（31/33）在V1导联之前，其余亚组均在V1导联之后。（6）I导联QRS波形态LCS组及ILCS组以负向波为主呈rs/rS型，分别为78.26%（72/92）及81.81%（27/33），RCS组以正向波为主呈R或r型76.67%（23/30）。结论在VOTPVC/VT的形态心电图鉴别标准中，胸导联移行指数对于鉴别LVOT与RVOT起源，具有较高的灵敏度、特异度、阳性预测值及阴性预测值，应被优先选用。     

囊袋收缩综合征的手术治疗

目的探讨白内障超声乳化术后囊袋收缩综合征的手术治疗效果。方法对12例（12只眼）白内障超声乳化术后并发囊袋收缩综合征进行囊袋松解术，观察术后视力及并发症情况。结果12只眼术后视力均有提高，10只眼视力〉10．4，2只眼视力0．1～0．3，无明显并发症发生。结论囊袋松解术是治疗重度囊袋收缩综合征的有效方法。     

The role of impulse oscillometry in detecting airway dysfunction in athletes

Background: Impulse oscillometry (IOS) has previously been proposed to provide greater sensitivity than spirometry when employed with indirect bronchoprovocation testing for the diagnosis of airway dysfunction in athletes. However, this recommendation is based on a highly selected population of symptomatic patients. Objective: To compare IOS, spirometry and respiratory symptoms following indirect bronchoprovocation in a screened cohort of athletes. Methods: One hundred and one recreational athletes were recruited. Respiratory symptoms were assessed via the Dyspnoea-12 questionnaire. Spirometry and IOS were performed pre and post a eucapnic voluntary hyperpnoea (EVH) challenge. Results: Ninety-four athletes completed the study. Sixteen athletes (17%) were positive for airway dysfunction based on spirometry (i.e. ≥10% fall in FEV₁) and 17 athletes (18%) based on IOS (i.e. ≥50% increase in R₅). Only nine athletes (10%) met both diagnostic thresholds. A poor relationship was observed between respiratory symptoms (i.e. Dyspnoea-12 score) and all spirometry and IOS variables. A direct relationship was observed between percentage change in R₅ (r?=?0.65), Z₅ (r?=?0.68), R_F (r?=?0.65), A_X (r?=?0.69) and the maximum fall in FEV₁ (ΔFEV₁max; p?<?0.001). A weak relationship was observed between R₂₀ (r?=?0.27), X₅ (r?=?0.37) and ΔFEV₁max (p?<?0.01). Conclusion: Impulse oscillometry and spirometry do not concur precisely following indirect bronchoprovocation. However, IOS detects additional cases of airway dysfunction in athletes and therefore may provide diagnostic value in this population. Further work is required to establish diagnostic thresholds and fully determine the place of IOS in screening athletes for airway dysfunction.