房间隔缺损的超声诊断及价值

目的:分析房间隔缺损的超声诊断方法,探讨其临床价值。方法:对疑似房间隔缺损患者进行超声诊断,与血管造影或者手术确诊的结果比对,判断超声诊断的准确率。结果:本研究中的40例房间隔缺损中2例多发,其余单发。I孔型4例和Ⅱ孔型37例以及静脉窦型1例。均有不同程度的右室扩大,其中Ⅱ孔型中,伴轻度三尖瓣返流25例,伴重度三尖瓣返流3例,并伴二尖瓣狭窄1例。手术符合率为97.5%。结论:超声诊断房间隔缺损准确率高,具有重要临床价值。     

检测心脏病变的MBE-1型普通心导管

MBE-1型普通心导管可用于肺心病、冠心病、肥厚性心肌病、先天性心脏病,如房间隔缺损、室间隔缺损、肺动脉瓣狭窄、Fallot氏三联症、四联症、大血管错位,以     

实时三维超声心动图评价房间隔缺损的收缩形式及其影响因素

目的应用实时三维超声心动图(RT-3DE)技术评价继发孔型房间隔缺损(ASD)在心动周期中的收缩变化特征并探讨其可能的影响因素.方法对36例继发孔型ASD患者进行实时三维成像,3例患者因图像质量欠佳而剔除,在其余33例病例,结合三维数据工作站,分别测量缺损面积,缺损长轴及短轴上的最大及最小径,平行及垂直于三尖瓣水平的最大及最小径.计算上述测值的变化率,并将缺损面积的变化率与缺损最大径、年龄、心率、肺循环与体循环血流量之比(Qp/Qs)进行相关分析.结果缺损面积在心动周期的收缩变化显著,变化率从15.2%到76.9%,平均变化率为49.0%.缺损呈对称性收缩且与缺损最大径、心率、Qp/Qs无相关性,与年龄呈轻微负相关.结论RT-3DE可清晰显示ASD缺损的动态收缩变化特征,有助于理解心房水平分流的病理生理学改变.     

可注射磷酸钙骨水泥及其应用

可注射磷酸钙骨水泥作为一种新型人工骨替代材料,以其良好的生物相容性和骨传导性被广泛应用于临床骨缺损和牙缺损的修复.本文介绍了可注射磷酸钙骨水泥的种类和特性,指出了存在的问题和应用前景.     

细菌视紫红质在生物传感器中的应用进展

生物传感器是生物敏感材料、理化换能器与电信号放大装置等多学科交叉的综合集成技术装置.典型的生物传感器以特异性感知的生物活性材料作为敏感元件,结合基于微电子器件的物理化学换能器和调理电路,实现生物敏感信息的电信号转换及放大.换能器的灵敏度、抗干扰能力等因素直接影响生物传感器的性能.从嗜盐菌中提取的细菌视紫红质是一种具有良好光敏特性的生物材料,可直接将光信号转化成电信号,从而实现将敏感元件和换能器合二为一的功能,已广泛应用于多种生物传感器中.细菌视紫红质的感光灵敏度和稳定性适用于开发具有颜色灵敏度的光传感器,最早的应用方向是人工视网膜;其光敏感和换能一体化特性可实现使用单个传感元件进行光学运动检测的功能,应用可扩展到运动传感领域.除了在视觉传感领域的应用,细菌视紫红质在病原体检测、水体pH检测、细胞膜电位检测等领域均表现出良好的灵敏性、稳定性和特异性.其不仅在生物传感领域具有应用价值,而且为半导体传感方法的研究提供了新途径.本文在简述细菌视紫红质的质子泵和光电响应特性等基本功能的基础上,阐述了细菌视紫红质构建生物传感器的应用进展,分析了不同传感器的特点,以期为细菌视紫红质的机理及其应用研究提供参考.     

静电纺丝纤维涂层对金属的防腐蚀效果

静电纺丝技术装置简单、成本低,可纺物质多、工艺可控,已在生物医用、过滤及防护、催化等领域广泛应用.用该技术制备的直径在微米和纳米之间的纤维,可直接用作防腐蚀涂层,也用作纳米容器自愈合涂层.主要介绍了静电纺丝在金属防腐蚀领域的应用,并指出了未来的发展方向.     

骨与牙釉质组织的生物矿化及磷酸钙材料仿生合成研究进展

骨和牙釉是典型的有机基质介导生成的生物矿化材料,其中的矿物相都属于以磷灰石为主的钙磷酸盐系统,但有机基质的不同使得晶体尺寸、形貌及排列方式迥异.本文综述了有关骨和牙釉组织的生物矿化研究,重点探讨对这些天然生物矿化组织的分级结构、基质蛋白的自组装及调控矿化机理的认识.在此基础上,磷酸钙材料的仿生合成以期应用于硬组织的缺损修复或再生医学也是目前的重要研究内容.     

光学生物传感器的研究进展

生物传感器是一种在多学科交叉背景下发展起来的新型测试装置,其中光学生物传感器因具有快速、灵敏、准确和高选择性等特点而最为引人瞩目.综述了光学生物传感器的原理、结构和分类;对比讨论了各类光学生物传感器的特性、应用领域、存在的主要问题及其今后的发展趋势;评述了以新型无机材料作为标记物的光致荧光生物传感器的研究意义以及发展前景.     

基于荧光法生物气溶胶监测仪计数效率评价及方法研究

生物气溶胶监测仪是一类快速、实时监测空气中生物气溶胶的新兴仪器。为系统评价生物气溶胶监测仪的计数效率,开展了荧光法生物气溶胶监测仪总粒子和荧光粒子2个通道的计数效率评价。首先设计搭建了1套生物气溶胶监测仪计数效率评价装置,然后通过表面原子转移自由基聚合反应(SI-ATRP)制备了单分散、荧光性质稳定的荧光聚苯乙烯微球。采用制备的荧光微球雾化法发尘,模拟生物气溶胶环境,开展计数效率的评价,总粒子数和荧光粒子数计数效率分别为98.9%和98.1%,评价结果表明搭建的装置能满足荧光法生物气溶胶监测仪计数效率的评价需求,对生物气溶胶检测具有意义。     

生物质热解液化装置研制与试验研究

介绍了一种电热式快速流化床生物质热解液化装置的研制，该装置的技术关键是采用两级螺旋进料和大流量喷雾直接冷凝收集生物油。试验结果表明，该装置完全可以用于各种固体生物质的热解液化，而且无论何种生物质都存在最佳热解温度。木屑、稻壳、玉米秆和棉花秆4种原料在最佳热解条件下的生物油质量产率分别为63%，53%，57%和56%，热值均为17～18MJ/kg。通过试验研究还发现，生物油是一种复杂的含氧有机化合物和水组成的混合物，包含了几乎所有化学类别的有机物；减少原料携带的外在水可有效降低生物油中的水分；储藏时间达半年的生物油仍然可以直接燃烧。     

Evaluation of materials for artificial heart valves

The heart of a normal human being beats about 38 million cycles every year. An artificial heart valve, to perform at this rate in the adverse conditions inside the heart for 20 years or more, should be highly wear-resistant with excellent fatigue strength. Thus, the study of mechanical and physical properties of the materials intended for use in artificial valves becomes an inseparable part of the valve development process itself. The physical and mechanical requirements of the materials used in the Chitra heart valve have been evaluated by studying their water absorption, adhesive wear and abrasive properties. The mechanical durability of the device has been assessed by accelerated life cycle testing. The test systems developed for the above are described here. The results show UHMW-PE to be a highly wear-resistant material suitable for the occluder. The accelerated wear tests show that the valve with Haynes-25 alloy cage and UHMW-PE disc has durability in excess of 50 years.     

Medical Outcomes Trust Conference presents dramatic advances in patient-based outcomes assessment and potential applications in accreditation

BACKGROUND: At its fourth annual State-of-the-Art Health Outcomes Conference, November 2, 1998, the Medical Outcomes Trust (Boston) convened experts to review advances in outcomes assessment technology and potential applications in clinical trials, clinical practice, and accreditation. KEYNOTE ADDRESS: "Future Directions in Health Status Assessment" identified what needs to happen next in order to put patient-defined outcomes into the databases used in medical decision making. Advances include a major recalibration of the SF-36 and SF-12 instruments from the Medical Outcomes Study (MOS) offering new norm-based scoring and the new methodology known as Dynamic Health Assessment (DynHA), which uses a computerized interactive process to select questions to produce a briefer but more precise assessment. CHOOSING COMPUTER SOFTWARE: A detailed needs assessment should be made and submitted to vendors to identify the best software for outcomes management in a particular organization. OUTCOMES IN CLINICAL TRIALS: Scientific and regulatory requirements differ between clinical trials and clinical practice, as seen in health status measurement of pain (migraine and osteoarthritis) and in antiretroviral therapies for patients with HIV (human immunodeficiency virus) disease. OUTCOMES ASSESSMENT IN SPECIFIC DISEASES: Similarities and distinctive challenges are identified in outcomes measurement of depression, low back pain, and congestive heart failure. OUTCOMES IN ACCREDITATION: Efforts are ongoing in integrating outcomes measures into the accreditation process for physicians, health care organizations, and health care plans. HEALTH OF SENIORS/MEDICARE HEALTH OUTCOMES SURVEY (HOS): The Health Care Financing Administration is unrolling the first patient-based outcomes measure to assess the quality of care provided to the Medicare population in managed care organizations.     

Scavenging of reactive oxygen and nitrogen species with nanomaterials

Reactive oxygen and nitrogen species (RONS) are essential for normal physiological processes and play important roles in cell signaling, immunity, and tissue homeostasis. However, excess radical species are implicated in the development and augmented pathogenesis of various diseases. Several antioxidants may restore the chemical balance, but their use is limited by disappointing results of clinical trials. Nanoparticles are an attractive therapeutic alternative because they can change the biodistribution profile of antioxidants, and possess intrinsic ability to scavenge RONS. Herein, we review the types of RONS, how they are implicated in several diseases, and the types of nanoparticles with inherent antioxidant capability, their mechanisms of action, and their biological applications.     

Methods derived from nonlinear dynamics for analysing heart rate variability

Methods from nonlinear dynamics (NLD) have shown new insights into heart rate (HR) variability changes under various physiological and pathological conditions, providing additional prognostic information and complementing traditional time- and frequency-domain analyses. In this review, some of the most prominent indices of nonlinear and fractal dynamics are summarized and their algorithmic implementations and applications in clinical trials are discussed. Several of those indices have been proven to be of diagnostic relevance or have contributed to risk stratification. In particular, techniques based on mono- and multifractal analyses and symbolic dynamics have been successfully applied to clinical studies. Further advances in HR variability analysis are expected through multidimensional and multivariate assessments. Today, the question is no longer about whether or not methods from NLD should be applied; however, it is relevant to ask which of the methods should be selected and under which basic and standardized conditions should they be applied.     

Recent Advances in Managing Atherosclerosis via Nanomedicine

Atherosclerosis, driven by chronic inflammation of the arteries and lipid accumulation on the blood vessel wall, underpins many cardiovascular diseases with high mortality rates globally, such as stroke and ischemic heart disease. Engineered bio‐nanomaterials are now under active investigation as carriers of therapeutic and/or imaging agents to atherosclerotic plaques. This Review summarizes the latest bio‐nanomaterial‐based strategies for managing atherosclerosis published over the past five years, a period marked by a rapid surge in preclinical applications of bio‐nanomaterials for imaging and/or treating atherosclerosis. To start, the biomarkers exploited by emerging bio‐nanomaterials for targeting various components of atherosclerotic plaques are outlined. In addition, recent efforts to rationally design and screen for bio‐nanomaterials with the optimal physicochemical properties for targeting plaques are presented. Moreover, the latest preclinical applications of bio‐nanomaterials as carriers of imaging, therapeutic, or theranostic agents to atherosclerotic plaques are discussed. Finally, a mechanistic understanding of the interactions between bio‐nanomaterials and the plaque (“athero–nano” interactions) is suggested, the opportunities and challenges in the clinical translation of bio‐nanomaterials for managing atherosclerosis are discussed, and recent clinical trials for atherosclerotic nanomedicines are introduced.     

基于HRV非线性特征的心律不齐自动分析

心率变异性(HRV)信号包含大量心脏和心血管系统的生理和病理信息,对其进行深入分析可以帮助诊断和预警心律不齐等心脏疾病.论文利用MIT-BIH心电数据库,提取正常心律和心律不齐两种心电数据并进行信号预处理以消除噪声干扰;采用小波变换提取小波系数的模极值和过零点以得到心电R波信号,计算其一阶差分得到HRV序列.然后,提取HRV信号的小波熵、近似熵和基本尺度熵3种非线性特征,并对正常心电和心律不齐心电特征进行差异统计检验.仿真结果表明,HRV信号的非线性特征可以有效地识别正常心律和心律不齐心电信号.     

Cardiovascular disease research in Saudi Arabia: a bibliometric analysis

In the previous three decades, in Saudi Arabia, prevalence of cardiovascular diseases (CVD) has increased and the government has invested significantly in education, healthcare, and research. This study examined the research productivity trends and characterized the types and focus of the all CVD research studies from Saudi Arabia. Data were extracted from studies published up until December 2015 and indexed in the PubMed database. Study eligibility criteria included: (1) sample selected within Saudi Arabia, and (2) CVD or a risk factor for CVD as an outcome, or (3) patients with CVD as study participants. Bibliometric data and study characteristics were extracted from each study; examples include authorship (number, gender, affiliation), journal, publication year, study location, research design, sample size, sample type (general or patient), sample composition (male or female), and sampling strategy (random or non-random). Analysis included 295 studies that pertained to 19 types of CVD; the most common were coronary artery disease (18%), hypertension (16%), stroke (14%), peripheral artery disease (11%), and congenital heart disease (10%). In the past 30 years, the overall productivity, use of a hypothesis-testing design (i.e. case–control, cohort, or trial), international collaborations, and funding increased incrementally. The experimental design constituted only 3% of all studies and less than 10% of the hypothesis-testing design studies. The scientific literature from Saudi Arabia addressed many of the CVD types. However, there were very few experimental studies conducted to date. Funding agencies should consider patronizing more studies with a hypothesis-testing design.     

Development of double sided linear pulse motor

Several novel design processes have been employed to develop two types of small linear pulse motors (LPM) with high thrust and high reliability. These LPMs are small enough for use in an implantable artificial heart. High thrust force is secured by means of a double-sided structure. A laminated core of cobalt steel plates and a rare earth magnet have been employed as the magnetic materials. One LPM has a two-phase, eight pole, four-coil construction and has been developed with the principal aim of miniaturization. The other has a two-phase, twelve-pole, two-coil construction and has been developed chiefly for ease of manufacture. Both types of LPM can have two to five times better input watt ratio, mass ratio, and volumetric ratio in relation to generated thrust than the conventional LPM     

The role of dialyzer membrane flux in bio-incompatibility

Dialyzer membrane flux is currently defined according to beta(2)-microglobulin (a middle molecule) clearance. Traditionally, high flux membranes were synthetic, and caused less inflammatory reaction in the extracorporeal circuit, compared with standard low-flux cuprophan bio-incompatible dialyzers. Initial reports suggested improved patient outcomes in acute renal failure when noncuprophan dialyzer membranes were used. However, over time these positive observations have not been substantiated. As the price differential between these dialyzer membrane types has become marginal, more high-flux dialyzers are now used in routine clinical practice. Two multicenter trials have recently reported a survival advantage for high-flux dialyzers. Whether this is directly consequent upon the choice of dialyzer membrane, or related to improvements in dialysate water quality, or changes in other clinical practices remains to be determined.     

Measuring the influence of clinical trials citations on several bibliometric indicators

The practice of publishing clinical trials in scientific journals is common, although not without its critics. This study aims to measure the effect of clinical trials citations on several bibliometric indicators: citations per document (CD); journal impact factor (JIF); relative h-index (RhI) and strike rate index (SRI). We select all the citable documents published in the NEJM, Lancet, JAMA, AIM and BMJ, for the period 2000-2004, and record the citations received by those papers from 2000 to 2005. Our results show that clinical trials have a CD significantly higher than those for conventional papers; JIF is lower when clinical trials are excluded, especially for NEJM, Lancet and JAMA. Finally, both RhI and SRI seem to be unaffected by clinical trials citations.