人工神经网络技术诊断肺心病的实验研究

笔者利用典型的人工神经(BP)网络反向传播模型构建了一个诊断肺心病的专家子系统.结果该专家子系统利用神经网络获取和表示临床有关数据和资料,较好地解决了自动知识的获取、表示、自学等问题,并对临床资料进行量化处理;实例测试表明,该系统有助于肺心病的早期诊断.     

Prediction of Compressive Strength of Sustainable Foam Concrete Using Individual and Ensemble Machine Learning Approaches

The entraining and distribution of air voids in the concrete matrix is a complex process that makes the mechanical properties of lightweight foamed concrete (LFC) highly unpredictable. To study the complex nature of aerated concrete, a reliable and robust prediction model is required, employing different machine learning (ML) techniques. This study aims to predict the compressive strength of LFC by using a support vector machine (SVM) as an individual learner along with bagging, boosting, and random forest (RF) as a modified ensemble learner. For that purpose, a database of 191 data points was collected from published literature, where the mix design ingredients, i.e., cement content, sand content, water to cement ratio, and foam volume, were chosen to predict the compressive strength of LFC. The 10-K fold cross-validation method and different statistical error and regression tools, i.e., mean absolute error (MAE), root means square error (RMSE), and coefficient of determinant (R²), were used to evaluate the performance of the developed ML models. The modified ensemble learner (RF) outperforms all models by yielding a strong correlation of R² = 0.96 along with the lowest statistical error values of MAE = 1.84 MPa and RMSE = 2.52 MPa. Overall, the result suggests that the ensemble learners would significantly enhance the performance and robustness of ML models.     

Impaired Anticoagulant Effect of Heparin in the Artificial Kidney: An Experimental Study

Bjo?rnson, J. &; Godal, H. C. Impaired Anticoagulant Effect of Heparin in the Artificial Kidney. An Experimental Study. Scand. J. clin. Lab. Invest. 36, 581–589, 1976.

Dialysis of blood and plasma was performed in vitro, in a ‘mini-Kiil’ dialyser as well as in dialysis bags. A marked shortening of the thrombin-clotting time was observed, indicating fall in heparin anticoagulant effect. The concentration of heparin, however, as measured by polybrene titration, was substantially less reduced. Fibrin formation, as evidenced by the ethanol gelation test, occurred more often in the dialysed than in the control plasma. In conclusion, the discrepancy between concentration and anticoagulant effect of heparin could be partly explained by influx from the dialysate of calcium, magnesium, and acetate ions. The fibrin-polymerizing effect of these ions was confirmed by a shortening of the clotting time with Reptilase, a proteolytic enzyme not influenced by thrombin inhibitors such as heparin. In addition, liberation of platelet factor 4 may be responsible for some reduction in antithrombin activity of heparin. No evidence of heparin being dialysed or adhering to the dialysis membrane was found.     

Antigen presentation on artificial acellular substrates: modular systems for flexible,adaptable immunotherapy

Background: Recent findings on T cells and dendritic cells have elucidated principles that can be used for a bottom-up approach to engineering artificial antigen presentation on synthetic substrates. Objective/methods: To compare the latest artificial antigen-presenting cell (aAPC) technology, focussing on acellular systems because they offer advantages such as easy tunability and rapid point-of-care application compared with cellular systems. We review acellular aAPC performance and discuss their promise for clinical applications. Results/conclusion: Acellular aAPCs are a powerful alternative to natural-cell-based therapies, offering flexibility and modularity for incorporation oSf a variety of stimuli, hence increasing precision. Current technologies should adapt physiologically important signals within safe materials to more closely approximate their cellular counterparts. These constructs could be administered parenterally as APC replacements for active vaccines or used ex vivo for adoptive immunotherapy.     

人工发酵虫草菌粉对糖尿病大鼠肾脏IL-17、p38 MAPK和NF-κB表达的影响

目的: 探讨人工发酵虫草菌粉对糖尿病大鼠肾脏白细胞介素17（IL-17）、p38 MAPK和NF-κB表达的影响。方法:雄性SD大鼠45只,随机选择15只为正常对照组（NC组）,其余30只大鼠通过一次性尾静脉注射链脲佐菌素（STZ,45 mg/kg）诱导建立糖尿病模型,造模成功的28只大鼠随机分为糖尿病组（DM组）和人工发酵虫草菌粉治疗组（虫草组,1 g/(kg·d）,每组各14只。虫草组给予每日1次人工发酵虫草菌粉溶液灌胃,NC组和DM组给予等体积生理盐水灌胃。18周末取材。计算肾重指数,检测血尿素氮（BUN）、肌酐（Scr）、24 h尿微量白尿蛋白（24 h UMA）。HE染色观察肾脏组织形态学变化;Masson染色观察肾脏纤维化程度;电镜观察各组大鼠肾小球超微结构改变;免疫组化法比较各组大鼠肾脏IL-17、p38 MAPK、NF-κB的表达水平。结果:(1) DM组肾重指数、BUN、Scr、24 h UMA较NC组明显升高,虫草组肾重指数、BUN、Scr、24 h UMA较DM组明显降低。(2) DM组肾脏纤维化明显,虫草组大鼠肾脏纤维化较DM组明显减轻。(3)电镜下,DM组大鼠肾小球毛细血管基底膜增厚,部分足细胞突起融合,系膜细胞增生;虫草组大鼠肾小球病变较DM组明显减轻。(4) DM组肾脏IL-17、p38 MAPK、NF-κB表达均显著上升,人工发酵虫草菌粉干预降低了肾脏IL-17、p38 MAPK、NF-κB的表达。结论:肾脏IL-17、p38 MAPK和NF-κB表达增多在糖尿病肾病发病过程中起到重要作用。人工发酵虫草菌粉可能通过减少肾脏IL-17、p38 MAPK、NF-κB的表达来改善糖尿病肾病。     

35例人工股骨头置换手术的配合

目的 探讨人工股骨头置换术的手术配合,减少手术感染的发生,保证手术的顺利进行和术后安全.方法 对35例人工股骨头置换患者的临床资料以及手术配合的整个过程进行分析,总结该手术的护理配合要点以及手术中注意事项.结果 35例人工股骨头关节置换手术均取得满意效果,术后无1例感染,均康复出院.结论 有效的手术配合是保证手术成功的关键.     

绷带卷加压包扎预防起搏器植入术后囊袋出血的应用效果

目的 探讨绷带卷加压包扎在永久心脏起搏器植入术后囊袋止血中的应用效果.方法 选取永久心脏起搏器植入患者591例,分为试验组和对照组.试验组(296例)用两个医用绷带卷并排放置于起搏器囊袋上方,与切口平行,3M胶布条固定绷带卷,松紧以伤口不出血、绷带卷无移位为准,术后6 h松解胶布条和绷带卷.对照组(295例)将1 000 g沙袋置于起搏器囊袋上方,术后6 h取走沙袋.比较两组患者压迫止血的安全性和有效性.结果 两组在切口出血、囊袋血肿和皮肤压力性损伤发生方面比较差异无统计学意义(P>0.05);试验组切口疼痛、尿潴留和睡眠障碍的发生率低于对照组,比较差异有统计学意义(P<0.05).结论 绷带卷加压包扎法可明显减少患者伤口疼痛、尿潴留、睡眠障碍的发生.     

羟考酮联合依托咪酯在无痛人流术中的应用

目的:探讨不同剂量羟考酮联合依托咪酯在无痛人流术中的应用效果.方法:选择拟行无痛人流术的早孕者120例,随机分为芬太尼组和羟考酮低、中、高剂量组,各30例.芬太尼组和羟考酮低、中、高剂量组分别缓慢静脉注射芬太尼1.0μg/kg和羟考酮0.05、0.1、0.15 mg/kg,5 min后静脉注射依托咪酯0.3 mg/kg,待受试者睫毛反射消失后进行手术.比较各组药物有效性和安全性.结果:各组睫毛反射消失时间、呼之睁眼时间和完全清醒时间差异均无统计学意义(P>0.05);芬太尼组和羟考酮中、高剂量组依托咪酯追加次数均明显少于羟考酮低剂量组(P<0.01).给予依托咪酯前至完全清醒各时点,4组受试者血压、心率、呼吸频率和脉搏氧饱和度间差异均无统计学意义(P>0.05).羟考酮中、高剂量组完全苏醒即刻及苏醒后30 min、2 h的宫缩痛评分均明显低于羟考酮低剂量组(P<0.01);羟考酮高剂量组完全苏醒即刻及羟考酮中、高剂量组苏醒后30 min、2 h的宫缩痛评分均低于芬太尼组(P<0.05～P<0.01).4组发生头晕、呼吸抑制、恶心和呕吐例数差异均无统计学意义(P>0.05);羟考酮中、高剂量组肌阵挛发生例数均少于芬太尼组和羟考酮低剂量组(P<0.05～P<0.01).结论:0.1 mg/kg羟考酮联合依托咪酯在无痛人流术中应用效果较好,且具有可减轻宫缩痛、减少肌阵挛发生的优点.     

老年患者人工股骨头置换的三维有限元分析

目的 对人工股骨头置换治疗的老年股骨转子间不稳定骨折有限元模型进行生物力学分析。方法 对1 名健康老年男性志愿者左侧股骨行螺旋CT 断层扫描后将数据导入Mimics14.0 软件得到股骨实体,获得左侧股骨转子间不稳定骨折模型。根据AML 生物型假体及Muller 骨水泥假体的设计参数,制作AML 普通柄、加长柄及骨水泥柄模型,并植入骨折模型中模拟3 种不同材料的人工股骨头置换术。将人工股骨头置换模型与正常股骨模型导入Ansys13.0 软件中,对各部分材料赋值后加载负荷并作应力分析。结果 正常股骨自近端至远端不断增加,并于中下段达到峰值。人工股骨头置换后并未改变股骨总体的应力趋势,同样是由近端到远端逐渐增加,应力集中部位为全长股骨中段,但股骨近端的受力小于正常股骨,同时股骨上最大等效应力增加。3 种假体受力集中部位均为骨髓腔峡部与假体连接处,假体的最大等效应力相近;3 种假体对股骨受力的影响趋势相同,但加长柄对股骨下端应力的改变小于普通柄,股骨的最大等效应力由高到低依次为加长柄、普通柄和骨水泥柄。结论 人工股骨头置换术用于Tronzo-Evans IV 型股骨转子间不稳定骨折可提高股骨的最大等效应力。     

NLR联合MLR对乙型肝炎病毒相关慢加急性肝衰竭患者人工肝治疗短期预后的预测价值*

目的 探讨中性粒细胞-淋巴细胞比例（NLR）联合单核细胞-淋巴细胞比例（MLR）预测乙型肝炎病毒相关慢加急性肝衰竭（HBV-ACLF）患者人工肝治疗短期预后的预测价值。方法 回顾性分析2016年1月—2019年6月广西壮族自治区民族医院收治的81例第一次行人工肝治疗的HBV-ACLF患者,根据90?d的预后情况将患者分为生存组63例和死亡组18例。采用多因素Logistic回归分析各相关因素与人工肝治疗的HBV-ACLF患者疾病转归的关系,通过绘制受试者工作特征（ROC）曲线分析NLR联合MLR的ROC曲线下面积（AUC）,评估两者联合预测HBV-ACLF患者人工肝治疗短期预后的价值。结果 人工肝治疗死亡组的血清总胆红素（TBIL）、肌酐、国际标准化比值（INR）、终末期肝病模型（MELD）评分、NLR、MLR、C反应蛋白（CRP）均高于生存组（P?<0.05）,凝血酶原活动度（PTA）低于生存组（P?<0.05）。多因素Logistic回归分析结果示：NLR [OlR=3.719（95% CI：3.525,3.942）]和MLR[OlR=2.335（95% CI：2.161,2.596）]为预测HBV-ACLF 患者人工肝治疗90 d短期预后的危险因素,PTA [OlR=0.729（95% CI：0.550,0.967）]为预测其预后的保护因素。AUC显示：NLR联合MLR的AUC相对最高,为0.921（95% CI：0.876,0.966）。NLR联合MLR可提高预测人工肝治疗的HBV-ACLF患者短期预后的敏感性[76.0%（95% CI：0.723,0.806）和特异性[92.0%（95% CI：0.882,0.957）]。结论 PTA和系统性炎症指标（NLR、MLR）与HBV-ACLF患者人工肝治疗短期预后密切相关。