Parametric phase-delay estimation of sound transmitted through intact human lung

Sonic noise between 300 and 1600 Hz is introduced into the mouths of 11 healthy adult male subjects at resting lung volume and is detected over the anterior extrathoracic trachea and at three sites on the right posterior chest wall. To overcome the difficulties associated with non-parametric phase unwrapping due to thoracic anti-resonances, the pahse delay τ(f) of propagation between the trachea and the chest wall is estimated using a linear parametric ARX-type statistical model with the non-parametric magnitude spectra as a guide. The resulting τ(f) estimates are unambiguous and reliable, and show a clear trend of decreasing τ(f) with increasing frequency, indicating that sound at higher frequencies reaches the chest wall faster than that at lower frequencies. This finding indicates that respiratory sound transmission is highly dispersive, most probably owing to frequencydependent airway and parenchymal wavespeeds.     

增殖性玻璃体视网膜病变D3级的玻璃体手术评价

本文分析了25例增殖性玻璃体视网膜病变(PVR)D₃级的玻璃体手术,成功率为68%.作者认为对PVR D₃级的治疗关键是玻璃体切除联合膜剥离及眼内填充,尤其是硅油填充可明显提高疗效.PVR形成与手术刺激、裂孔大小、外伤及玻璃体积血不关。对玻璃体手术的适应症，作者对手术时机及并发症也作了扼要讨论。 （中华眼底病杂志，1993，9：145-147）     

Maternal corneal thickness during pregnancy

We measured central corneal thickness in 89 pregnant women. It was increased 16 micron (P = .01) compared to the control eyes of 18 nongravid and 17 postpartum women. There was no significant difference (P = .79) in corneal thickness between the nongravid and postpartum groups. When comparing subjects by week of gestation, there was no trend over time in corneal thickness (analysis by linear regression). Intraocular pressure was lowered during pregnancy, but it did not correlate with corneal thickness for either the pregnant or nonpregnant group.     

Intestinal bacterial metabolism of flavonoids and its relation to some biological activities

Flavonoid glycosides were metabolized to phenolic acids via aglycones by human intestinal microflora producing α-rhamnosidase, exo-β-glucosidase, endo-β-glucosidase and/or β-glucuronidase. Rutin, hesperidin, naringin and poncirin were transformed to their aglycones by the bacteria producing α-rhamnosidase and β-glucosidase or endo-β-glucosidase, and baicalin, puerarin and daidzin were transformed to their aglycones by the bacteria producing β-glucuronidase, C-glycosidase and β-glycosidase, respectively. Anti-platelet activity and cytotoxicity of the metabolites of flavonoid glycosides by human intestinal bacteria were more effective than those of the parental compounds. 3,4-Dihydroxyphenylacetic acid and 4-hydroxyl-phenylacetic acid were more effective than rutin and quercetin on anti-platelet aggregation activity. 2,4,6-Trihydroxybenzaldehyde, quercetin and ponciretin were more effective than rutin and ponciretin on the cytotoxicity for tumor cell lines. We insist that these flavonoid glycosides should be natural prodrugs.     

TIMI血流计帧法测定冠状动脉血液流速在急性心肌梗死再灌注治疗中的应用

目的 :评价计帧法测定冠状动脉血流速度在急性心肌梗死 (AMI)再灌注治疗中的临床意义。方法 :90例急性心肌梗死患者行直接经皮冠状动脉成形术 (PTCA)、溶栓失败后的挽救性PTCA治疗和延迟PTCA治疗 ,梗死相关动脉成功再通 ,心肌梗死溶栓实验 (TIMI)血流分级 2级或 3级 ,用计帧法法测定梗死相关动脉(IRA)帧数 ,结合IRA长度测定血流速度 ,观察帧数、血流速度和心功能、近期临床预后的关系。结果 :IRA平均长度为 (119 30± 2 5 2 6 )mm ,平均CTFC为 (37 36± 19 70 )帧 ,平均流速为 (10 0 33± 4 1 92 )mm/s ,左室射血分数(LVEF)和IRA帧数负相关 (r =- 0 6 4 ,P =0 0 1) ,LVEF和IRA血流速度正相关 (r =0 74 ,P =0 0 0 )。住院期间有心脏不良事件组和无不良事件组间血流速度有统计学差异 (16 7 2 0± 36 75vs 10 5 78± 30 85 ,P <0 0 5 ) ,CT FC >30祯和 <30帧组间射血分数、住院期间心脏不良事件发生率有显著性差异 (P <0 0 5 )。Logistic多元回归分析发现血流速度是心脏不良事件的独立相关因素 (OR =2 4 1,95 %CI =1 95～ 2 83,P =0 0 0 )。结论 :计帧法测定IRA帧数和血流速度是一种较好的评价冠状动脉血流的方法 ,其结果和心功能、临床近期预后密切相关。     

恶性疟P190抗原保守区Ⅰ、Ⅴ基因的亚克隆及在大肠杆菌中高效表达

作者采用PCR方法克隆了我国海南省FCC1/HN株P190抗原两个保守区基因,分别定名为P190CRI和P190CRV。基因片段经纯化后连接到pUC18载体中进行DNA序列分析,结果显示:除了P190CRV中有5个碱基变换外,其余序列均与MAD20型序列一致。经序列分析的两个基因片段分别与pGEX-2T载体连接,经双酶切鉴定后转化感受态JM109(DE_3)大肠杆菌进行高效融合表达,并且用Sepharose 4B-谷胱甘肽层析柱进行亲和纯化,结果为:两个插入基因片段均得到高效融合表达,经一步亲和纯化后就取得高纯度的重组蛋白。     

Myoblast fusion in Drosophila melanogaster is mediated through a fusion-restricted myogenic-adhesive structure (FuRMAS).

During myogenesis in Drosophila embryos, a prominent adhesive structure is formed between precursor cells and fusion-competent myoblasts (fcms). Here, we show that Duf/Kirre and its interaction partners Rols7 (found in founder myoblasts and growing myotubes) and Sns (found in fcms) are organized in a ring-structure at the contact points of fcms with precursor cells, while cytoskeletal components like F-actin and Titin are centered in this ring in both cell types. The cytoplasmic protein Blow colocalizes with the actin plugs in fcms after cell adhesion. Furthermore, the requirement of additional as yet unidentified components was demonstrated by using mammalian C2C12 myoblasts. In this study, we propose that the fusion-restricted myogenic-adhesive structure (FuRMAS) is pivotal in linking cell adhesion as well as local F-actin assembly and dynamics to downstream events that ultimately lead to plasma membrane fusion. Moreover, we suggest that the FuRMAS may restrict the area of membrane breakdown.     

ECG心搏模式识别

心电图 (ECG)中的心律失常识别对临床分析有着非常重要的意义。本文阐述了心搏模式识别的基本思路 ,对国内外近年来心律失常识别的各种方法进行了分类与总结 ,并且针对不同方法的优缺点进行了详细的比较 ,深入探讨了各种方法存在的主要问题 ,最后指出心律失常识别技术的发展方向。     

小肝癌的病理与螺旋CT诊断

原发性肝癌(primaryhepatocellularcarcinoma,PH CC)在我国是居第3位的恶性肿瘤,每年患者达11万之多,预后甚差[1]。肝癌的早期诊断,是提高患者5年生存率的重要手段,也是影像学面临的重大课题。直径>3cm的病灶,各种影像学技术的检出敏感性均很高,无统计学差异。而对于小肝癌(SHCC),特别是微小肝癌(MHCC)的检出仍有一定困难,其检出敏感性有一定差异。以往文献报道术中超声、CT动脉门脉造影(CTAP)和碘油CT的敏感性最高,但均为创伤性检查,临床应用有严格指征。1989年螺旋CT机问世,其连续快速扫描和容积数据采集成像技术的应用,特别是近…