肝脏局灶性小占位的磁共振信号强度比与病灶性质的相关性

目的 计算肝细胞癌、肝转移瘤、肝脏海绵状血管瘤和肝囊肿的病灶／肝脏磁共振信号强度比（SIR）,并评价其与病灶性质的关系。方法 随机选择经确诊的肝细胞癌、肝转移瘤、肝海绵状血管瘤和肝囊肿病例共92例（148个病灶）行前瞻性磁共振成像（0．5T）研究。计算4种病灶的SIR,并进行统计学分析。结果 在T1W图像上,肝海绵状血管瘤与恶性肿瘤的SIR值间差异无显著性（t=1.799,P=0.075);质子加权像上,良恶性肿瘤的SIR之间无统计学意义（t=0.691,P=0.491);T2WI上,良性病变的SIR显著高于恶性肿瘤（P＜0．01）,且4种病变的SIR值与回波时间（TE）之间均存在线性正向相关关系。结论 在T2WI个测得的SIR可用于区分肝脏占位性病灶的性质。     

重烧氧化镁粉的活性测定

新型无机骨粘粘剂磷酸镁水泥（MPC）的主要反应物－重烧MgO的活性与MPC的性能密切相关。本文用比表面积法、碘吸附法、物相分析法、动力学分析法对不同MgO的活性进行了表征,并考察了重烧MgO的活性对MPC材料凝结时间、30min抗压强度以及水化温升的影响。结果表明,比表面积法、碘吸附法、物相分析法不能用于重烧MgO粉活性的测定,而动力学分析用于表征重烧MgO粉的活性是可行和可靠的。     

Can low intensity pulsed ultrasound (LIPUS) be used as an alternative to revision surgery for patients with non-unions following fracture fixation?

BackgroundNon-union is a significant complication of fracture fixation surgery, and can negatively impact a patient’s quality of life. Low intensity pulsed ultrasound (LIPUS) has been used to treat delayed or non-unions previously in the literature. The aim of this study was to determine the success rate of LIPUS treatment in patients with chronic fracture non-unions, and to establish the effect of systemic or local factors on its success.MethodsThis was a retrospective, observational study which included all patients undergoing LIPUS treatment in a single institution. Patients deemed suitable for LIPUS underwent treatment for a period of 6 months from initiation. They were followed up with sequential radiographs to assess union at intervals of 6 weeks, 3 months, 6 months and 1 year. LIPUS treatment was considered to be successful when patients achieved clinical and radiological union, without the need for revision surgery.ResultsA total of 46 patients were included in the study; 8 were lost to follow – up, leaving 38 patients for the final analysis. The mean age of patients was 47.03 ± 19.7 with a male to female ratio of 1.2:1. Union was achieved in 57.89%; the rest underwent revision surgery. There was no significant association between outcomes after LIPUS treatment and patients’ age, gender, smoking status or type of non-union. Patients with a small inter-fragment bone gap were more likely to have a successful outcome after LIPUS (p = 0.041). Time to treatment did not have a statistically significant impact on outcomes after LIPUS. Interestingly, all 6 patients with diabetes in the study managed to achieve union after LIPUS.ConclusionsThis study demonstrates that LIPUS is not successful in a large proportion of patients with established fracture non-unions. However, it does represent a low risk treatment modality as an alternative to revision surgery, especially for patients with diabetes who have a small inter – fragment bone gap. More research in the form of large randomised controlled trials needs to be carried out to further assess the role of LIPUS in the treatment of non-unions.     

运动疗法干预骨质疏松症研究进展及现存问题分析

骨质疏松症是一种与年龄和性别有关的全身性疾病,表现特征为每单位体积的骨量减少,骨强度受损,患者容易骨折,造成生活质量降低。运动疗法相比药物疗法具有经济性、无不良反应等优势,被越来越多人所关注。然而运动疗法的疗效在实际应用过程中并没有完全凸显,主要受运动本身的特点（运动方式、运动强度）以及患者自身条件所影响。目前骨质疏松症的检测方式具有一定的不确定性,患者无法判断经过一段时间运动干预后的真正疗效,从而影响到运动参与的积极性,并且运动干预骨质疏松症的评价指标主要集中在骨密度和骨矿物质含量上,忽视了运动对于人体肌肉功能以及身体机能的影响。另外,骨质疏松症人群的机能状态存在很大差异,因此,想要达到较好的干预效果就需要根据患者特点制定最为合适的运动处方。目前,国内外对运动干预骨质疏松症存在的问题尚缺乏详细的概述,笔者就相关现存问题进行归纳总结,给出建议以供参考,旨在提高运动疗法干预骨质疏松症的效果。     

不停跳冠状动脉旁路移植术中应用MostCare/PRAM监测系统进行血流动力学监测的临床研究

目的探究Most Care/PRAM系统监测下不停跳冠状动脉旁路移植术(OPCABG)患者术中血流动力学变化情况和预后分析。方法纳入2016年10月至2017年1月安贞医院89例OPCABG患者,其中男53例、女36例,年龄(60.50±8.40)岁。记录术中血流动力学变化情况。按是否发生心肌梗死、低心排血量等严重循环不良事件,分为平稳组和严重循环不良事件组,进行相关分析。结果手术全程监测完整血流动力学数据患者65例,开胸前和关胸后被动抬高试验的每搏量(SV)升高均值分别为23.00%±3.20%和29.40%±3.70%。麻醉、开胸、应用肝素时、搭桥中、应用鱼精蛋白时、关胸和术毕7个时间段,SV明显下降,外周血管阻力指数(SVRI)持续显著增加,最大压力梯度(d P/d T)和心脏循环效率(CCE)在麻醉后明显下降,搭桥时下降到最低,其后逐渐升高;每搏量变异率(SVV)和脉压变异率(PPV)在麻醉后下降,开胸后一直升高。89例患者发生严重循环不良事件共9例,其中4例死亡。严重循环不良事件组术中基础SVRI、SVV和PPV均显著高于平稳组(P<0.05),CCE、d P/d T和SV差异无统计学意义(P>0.05)。术中基础SVRI、CCE、d P/d T、SVV、PPV和SV均值与预后指标均无明显相关性。结论OPCABG术中易出现血流动力学的改变,因此,OPCABG术中宜应用Most Care/PRAM仪进行血流动力学监测,并及时纠正血流动力学异常。     

A Novel Iterative Penalty Method to Enforce Boundary Conditions in Finite Volume POD-Galerkin Reduced Order Models for Fluid Dynamics Problems

A Finite-Volume based POD-Galerkin reduced order model is developed for fluid dynamics problems where the (time-dependent) boundary conditions are controlled using two different boundary control strategies: the lifting function method, whose aim is to obtain homogeneous basis functions for the reduced basis space and the penalty method where the boundary conditions are enforced in the reduced order model using a penalty factor. The penalty method is improved by using an iterative solver for the determination of the penalty factor rather than tuning the factor with a sensitivity analysis or numerical experimentation.The boundary control methods are compared and tested for two cases: the classical lid driven cavity benchmark problem and a Y-junction flow case with two inlet channels and one outlet channel. The results show that the boundaries of the reduced order model can be controlled with the boundary control methods and the same order of accuracy is achieved for the velocity and pressure fields. Finally, the reduced order models are 270-308 times faster than the full order models for the lid driven cavity test case and 13-24 times for the Y-junction test case.     

高强度聚焦超声的原理和设备及临床应用

高强度聚焦超声(HIFU)是将超声的能量聚集在很小的区域内,通过高热量灼烧病变组织细胞,但不会对周围其他组织产生影响,因此,其被广泛应用于对肿瘤、大脑疾病和血管疾病的治疗中。现阶段,临床正尝试将磁共振引导的HIFU应用于神经外科手术治疗中,如治疗特发性震颤等。该研究简要回顾了HIFU的原理、设备和临床应用,叙述了其在肝脏、乳腺、前列腺、肾脏、子宫肿瘤治疗中的应用效果及应用前景。     

Fourier变换形状测试法测量关节面形状

本文应用富里叶变换形状测试技术（ＦＴＰ），针对人体关节测试研究，并从实际应用角度分析了ＦＴＰ技术的误差及其改进方法，对标准平板和标准圆柱面的测定结果表明，精度可以达到０．０５ｍｍ以上。     

不同年龄组正常人群影响最大胸椎后凸角的相关因素分析

目的：本研究通过对不同年龄组正常人群矢状位参数进行分析,旨在报道正常人群脊柱骨盆参数参考值范围,并探索不同年龄段引起最大胸椎后凸角改变的影响因素。 方法：本研究纳入自2015年1月至2018年月于两所医院健康体检中心的正常人群,收集人口统计学参数以及矢状位影像学参数。通过将人群分为≤40岁组与＞40岁组,对比分析不同年龄组人群的矢状位参数,并对不同年龄组影响最大胸椎后凸角max TK的因素进行相关性分析。结果：本研究共计纳入191例正常人群,其中≤40岁组94人,平均年龄为28.5±6.4岁;＞40岁组97人,平均年龄为53.9±8.3岁。不同年龄组人群在胸1椎体矢状位倾斜角T1 Tilt（18.6±6.5 vs. 20.6±5.5, P=0.023）, 胸椎后凸下端椎倾斜角TVA（15.3±5.3 vs. 17.5±6.6, P=0.013）,max TK（33.9±8.3 vs. 38.0±9.4, P<0.001）,max LL- max TK（14.9±8.9 vs. 12.3±9.4, P=0.048）及矢状面躯干偏移SVA（-2.5±21.8 vs. 6.1±20.9, P=0.006）上存在显著差异。在年龄≤40岁的人群中,T1 Tilt、TVA、max LL及骶骨倾斜角SS与max TK显著相关,而在年龄＞40岁的人群中,年龄、T1 Tilt、TVA、max LL及骨盆入射角PI与max TK显著相关。结论：max TK随着年龄增长呈现上下均匀增长趋势,在＞40岁的人群中,max TK与年龄呈现正相关关系。此外,不同年龄阶段,骨盆对于max TK改变的代偿呈现出不同的模式。     

投影遗传算法

针对一般遗传算法在求解优化问题的多个优化解时的局限性,结合曲面投影与遗传算法的基本思想,提出了一种基于曲面投影的投影遗传算法用于解决此类问题,数值验证的结果表明了本算法的有效性和实用性。