Neural classifier construction using regularization, pruning and test error estimation

In this paper we propose a method for construction of feed-forward neural classifiers based on regularization and adaptive architectures. Using a penalized maximum likelihood scheme, we derive a modified form of the entropic error measure and an algebraic estimate of the test error. In conjunction with optimal brain damage pruning, a test error estimate is used to select the network architecture. The scheme is evaluated on four classification problems.     

High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel

Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 10⁷ cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit.     

The correlation of ureaplasma urealyticum infection with infertility

Summary. A prevalence study of Ureaplasma urealyticum (UU) infection of the male genital tract was carried out in Shanghai between March 1992 and June 1995. Significantly higher frequency of UU infection was found among infertile males (549/1416) as compared to fertile controls (34/375). Examination of 8 specimens each from infertile men and fertile subjects by electron microscopy, immunogold and immunofluorescence techniques, demonstrated adhesion of Ureaplasma urealyticum to the membrane of spermatozoa and exfoliated germ cells. In addition, gold particles on Ureaplasma urealyticum were found to be adhered to the sperm surface in 4 of the 8 samples. Strong specific anti-UU fluorescence was detected in 6 of 8 samples, mainly on the midpieces and post-acrosomal regions of the spermatozoa.
To further study the effects of Ureaplasma urealyticum on fertility, 47 male Sprague-Dawley (SD) rats were infected artificially with Ureaplasma urealyticum serotype 8 (T960). Morphological changes in the seminiferous tubules were observed 3–5 weeks after inoculation in the sacrificed animals. Dramatic impairment of spermatogenesis of both testes was found in 11 rats. Mating experiment confirmed infertility in 12 of 40 rats. Offsprings of the infected rats were significantly smaller than those of controls in terms of prenatal weights and birthweights.     

人工全膝关节置换术疗效探讨

探讨提高人工全膝关节置换术疗效的因素。总结人工全膝关节置换 1 5例 1 7膝 ,其中 OA6膝 ,RA3膝 ,创伤性关节炎 1膝 ,选用髁式表面假体 ;骨肿瘤 5膝 ,术后失败翻修 2膝 ,选用绞链式假体。结果 :短期随访显示功能良好 ,疼痛消失 ,全部重返生活和工作 ;KSS评分绞链膝 84～ 92分 ,平均 88分 ;表面膝 85～ 94分 ,平均 89分。结论 :只要选择合适的病例 ,设计合理的假体 ,人工全膝关节置换效果非常肯定     

Artificial trachea reconstruction with two-stage approach using memory-alloy mesh

Artificialtrachealprosthesisisnowachallengetotheentiresurgicalfieldallovertheworld Previously ,allkindsofprosthesiswere“innerstent”thatcouldnotbeintegratedwithnativetrachea Sincethereisaninterfacebetweensmoothsurfaceofthe prosthesisandlivingtissues,andtheinnersideoftheprosthesisisnotcoveredwithlivingmembrane,infectionsalwayshappenaroundtheprosthesis Wethendevelopedanewtechnique,whichcombinedmemory alloymeshwithtraditionaloperativeprocedures Memory alloymeshisextensible,flexibleandcanmaintain…     

人工心脏起搏器的植换

探讨人工心脏起搏器植换方式选择。方法：起搏器植换２２例，其中，能源耗竭１４例，感知和起搏功能障碍４例，囊袋感染破溃致ＰＭ外露４例。非感染者起搏阈值，〈２．５Ｖ，行原位植换：ＰＴ值〉３．０Ｖ或有感染者，更换全套起搏系统。结果：非感染的１８例中，１０例ＰＴ〈２．５Ｖ，实行原位植换；８例ＰＴ值〉３．０Ｖ和其余４例有感染者，植入新的起搏系统。     

Factors affecting the neonatal response to artificial surfactant

Objective : To define the individual neonatal response to the artificial surfactant, Exosurf, and factors that may influence the response.
Methodology : Eighty-two consecutive, preterm neonates with respiratory distress syndrome, who received Exosurf at <12h of age were studied. Their response was categorized from the graphical change in the oxygenation index with postnatal age, for 12h after each of two doses of surfactant and assessed independently by two observers. Clinical factors were analysed for their effect on the four pre-defined categories of response, namely: none; mild; good; relapsed; and good: sustained.
Results : Within the first 12h, 11% of the neonates showed no response, 5% a mild response and 84% a good response, but 34% relapsed. By 24h, 6% still showed no response (all died), 11% showed a mild response and 83% a good response, of whom half relapsed. At 24h, no response was significantly associated with low gestational age and asphyxia mild response with less severe lung disease. According to the response there was a gradation in the risk of death during the first week.
Conclusions : The response to Exosurf can be individually and reproducibly categorized and demonstrated that 83% of neonates had a good response but half relapsed. No response was associated with extreme prematurity and asphyxia     

微晶蜡非催化氧化反应的神经网络模型

对微晶蜡进行了非催化空气氧化，并利用人工神经网络将氧化微晶蜡的酸值、酯值及微晶蜡的氧化条件（反应温度、空气流量和反应时间）进行关联，建立了微晶蜡非催化氧化的酸值、酯值的神经网络模型，并用该模型预测了反应条件对微晶蜡氧化反应过程的影响。结果表明，该模型不但具有较高的计算精度，而且具有满意的预测能力。     

间断头高位与站立位可对抗模拟失重大鼠股动脉收缩反应性的降低

目的 观察和比较头高位（HUT）与站立位（STD）对模拟失重所致股动脉收缩反应性降低的影响及其时间依赖性。方法 49只雄笥SD大鼠随机分为对照组、模拟失重组、头高位2h组、头高位4h组、站立位1h组、站立位2h组和站立位4h组，每组7只。利用离体股动脉血管环技术测定7组大鼠股动脉对血管收缩剂的反应。结果 悬吊大鼠股动脉血管环对KCl和苯肾上腺素的收缩反应性显降低，头高位与站立位组大鼠的股动脉血管环对KCl和苯肾上腺素收缩反应均较悬吊组显增强，与同步对照组相比已无显差异。结论 4wk模拟失重可以使大鼠股动脉的收缩反应性降低，而头高位与站立位均可对抗大鼠股动脉的收缩反应性的降低，这些结果提示间断性人工重力可对抗失重对血管所产生的影响。     

CDIC人工牙种植体的临床应用

目的：探讨种植牙的临床应用及酯套冠的修复疗效。方法：对80例失牙患者植入CDIC锥状螺旋种植体94枚，术后7－10d行暂时冠修复，6个月左右行永久性酯套冠修复。结果：随访2－5年，种植成功率达91.5%（86／94)。结论：3M聚碳酸酯套冠安全可以替代烤瓷牙冠作为前牙种植体的上部结构，CDIC锥状螺旋种植体操作方法简单，配合酯套冠修复成功率高，适合在基层医院推广应用。