Laboratory evaluation of hypercoagulable states

The number of well-characterized hereditary and acquired hypercoagulable conditions is increasing, such that in many thrombophilic patients, the laboratory can now identify a hypercoagulable condition. This review describes the currently known hypercoagulable states that predispose patients to venous, and in some instances, arterial thrombosis. For each condition, the discussion includes the incidence, magnitude of the thrombotic risk in the general population in comparison with symptomatic families, synergistic interactions among the various hypercoagulable conditions, molecular pathogenesis, and interpretation of laboratory test results. In addition, recommendations for laboratory testing are summarized.     

Laboratory evaluation in the diagnosis of Lyme disease

PURPOSE: To provide a qualitative evaluation of the predictive value of the laboratory diagnosis of Lyme disease and to use the resultant data to formulate guidelines for clinical diagnosis. DATA SOURCES: A MEDLINE search of English-language articles or articles with English-language abstracts published from 1982 to 1996. DATA EXTRACTION: Sensitivity, specificity, and likelihood ratios were calculated, and a random-effects model was used to combine the proportions from the eligible studies. Prespecified criteria were used to determine which studies were eligible for analysis. DATA SYNTHESIS: Laboratory testing in general is not clinically useful if the pretest probability of Lyme disease is less than 0.20 or greater than 0.80. When the pretest probability is 0.20 to 0.80, sequential testing with enzyme-linked immunosorbent assay and Western blot is the most accurate method for ruling in or ruling out the possibility of Lyme disease. CONCLUSIONS: Laboratory testing is recommended only in patients whose pretest probability of Lyme disease is 0.20 to 0.80. If the pretest probability is less than 0.20, testing will result in more false-positive results than true-positive results; a negative test result in this situation effectively rules out the disease.     

Investigation of Bonding Behavior of AA1050/AA5083 Bimetallic Laminates by Roll Bonding Technique

In this study, 1-mm AA1050/AA5083 bimetallic laminates were produced using roll bonding (RB) process. The RB process was carried out with thickness reduction ratios of 25, 50 and 75%, separately. Finite element simulation was used to model the deformation of bimetallic laminates for various experimental conditions. Particular attention was focused on the bonding of the interface between AA1050 and AA5083 layers in the simulation. The optimization of thickness reduction ratios was obtained for improvement of the bond strength of bimetallic laminates during RB process. During the simulation, the mean equivalent strain at the interface zone between the layers was found to reach the maximum value with a high quality bond for the sample produced with 75% of thickness reduction. Moreover, the fracture surface of samples around the interface of laminates after the tensile test was studied to investigate the bonding quality by scanning electron microscopy.     

Understanding of Void Formation in Cu/Sn-Sn/Cu System During Transient Liquid Phase Bonding Process Through Diffusion Modeling

Metallurgical and Materials Transactions B - Transient Liquid Phase (TPL) bounding of Sn foil sandwiched between two Cu foils involves, in the temperature range above the melting point of Sn...     

Laboratory testing in the evaluation of male infertility. A rational approach

Alpha radiation dosage is an important occupational health factor in the mining of uranium and mineral sands. Alpha radiation induced errors in the data of silicon based memory chips provide the foundation for a new type of sensor, with the potential for affordable and prompt measurement of personal alpha doses. With particular reference to Dynamic Random Access Memories (DRAM) this paper introduces the operating principle of a memory based radiation sensor, which is the error mechanism in silicon integrated circuits.     

硅/硅键合新方法的研究

研究成功用Ⅳ族元素锗进行硅／硅键合的一整套新技术（代替通用的亲水法）;实现了键合层无孔洞,边沿键全率达９８％以上,键合强度达２１５６Ｐａ以上,并通过在锗中掺入与低阻同型号的杂质,实现了应力补偿。     

新型的溶气浮选实验室系统

介绍了一种根据溶气气浮原理建立起来的细粒浮选实验室系统,对包钢铁矿石的带矿试验证明了其一定的实川性和优越性．     

铜、铁、铜叠片热轧复合的数值模拟

利用ABAQUS有限元软件对Cu、Fe、Cu叠片进行了轧制复合热力耦合模拟。获得了轧制复合过程的应力一应变场和温度场变化,对热轧过程有了更清晰的认识;数值模拟与试验结果吻合良好,复合板各层厚度变化误差在5%左右,可对预测产品厚度,同时对工艺的制定提供理论指导。     

Laboratory evaluation of tissue heart valves. A comparative assessment

Tissue of commercially prepared tissue heart valves were evaluated and compared with aluminium treated, fixed porcine valve tissue in vitro (tensile strength, scanning and transmission electron microscopy) and in vivo (calcification potential after subcutaneous implantation in the rat model). Valve leaflets (n = 40) were divided into four groups according to the method of treatment: Group I (fixed in 0.652% glutaraldehyde, control), Group II (fixed and treated with aluminium), Group III (fixed and treated with Toluidine blue) and Group IV (fixed and treated with watersoluble alkyl sulphate). Tensile strength was not influenced in Group II and III (p > 0.05). Group IV indicated a significant (p < 0.05) reduction in tensile strength. Scanning electron microscopy revealed damage and loss of surface endothelium in Group III and IV respectively. Transmission electron microscopy indicated damage to underlying matricial cells in Group III and IV. Calcification potential was significantly (p < 0.001) reduced in Group II to IV. We conclude that damage ultrastructure could contribute to the reduced tensile strength in Group IV and that reduced tensile strength might have an influence on the long-term durability of tissue heart valves. Antimineralization treatment of tissue heart valves does retard calcification but is yet unable to inhibit the process completely.     

生物质用于焦炭和烧结生产的实验室评价

生物质作为碳可供选择的环保替代燃料,用其进行炼焦和炼铁是一个非常好的选择,因此,应该积极调查、研究如何采取不同的方法利用生物质,以减少硫化物、氮氧化物、二氧化碳的排放和可能的成本投入。对生物质在炼焦生产与烧结生产中的实用性在独立的试验中进行评估。生物质对炼焦生产的实用性研究如下:将1%～5%的木质生物质或是焙烤(轻度热解)的木质生物质作为部分高挥发性煤的替代物添加至配合煤中,在实验室焦炉中进行碳化试验。试验结果表明,当把粉碎的生物质加入到配合煤后,焦化压力显著降低,同时焦炭的硫含量下降,但是焦炭的高温强度和力学性能亦有轻微下降,但这种实测强度的降低需要进一步的研究。另外,在一系列独立试验中,通过利用生物质(分别是锯末、粉碎的玉米芯、树皮、木炭等)作为烧结用粉焦的替代燃料在实验室烧结锅进行评估。试验中,燃料用10%、20%、30%、40%的生物质代替。试验结果显示,烧结混合料的堆密度和烧结时间都有下降,添加了生物质的烧结矿质量没有显著恶化。这些初步的试验表明,在实际的炼焦与炼铁生产中生物质很有可能作为一种可再生能源替代部分传统的化石燃料。为了某种特定应用而进行产品优化则需要额外试验。     

工程围岩岩爆的实验室综合评判方法

在多种岩爆室内试验评价指标中,在考虑岩爆发生机制基础上选用围岩应力指数、岩体脆性指数、岩体完整性系数、弹性能量指数4个指标进行岩爆的模糊数学综合评判。对岩爆发生及烈度倾向进行了预测。并选用不同工程围岩岩体在室内进行岩爆模拟性试验。结果发现和预测情况比较相符,证明了岩爆预测方法的有效性。     

Reasons Underlying a Mandatory High Penalty Construction Contract Bonding System

Mandatory high penalty conditional bond in public works features the current U.S. construction contract bonding system, which is unique to the low penalty unconditional bond, a more popular choice on the international market. The diversity of construction contract bonding practices puzzles many transitional economies in their globalization processes, when they are to establish or reform their construction contract bonding system. Based on the research into surety bonding mechanisms, this paper illustrates that the penalty requirement is a controlling factor, and that only high penalty conditional bond and low penalty unconditional bond can bring a state of equilibrium to the market. The conditional bond is fairer, and a high penalty conditional bond is a more functional choice than the low penalty unconditional bond. However, lack of enough demand and experienced sureties hampers the application of high penalty condition bonds. Being the nominal owner of public works, the government can always save its money from construction contract bonding system and start up the demands. Therefore, a mandatory surety bonding system in public works with a high penalty requirement should be a good public policy choice for the government.     

9900型靶材与靶托的连接技术

针对９９００型靶材与靶托的连接中存在的难题分析其原因,对此采取了一些措施,通过靶材大小,焊料的改进和热处理等,实现了Ｎｉ－Ｃｒ合金、铬、银靶与铜底托的连接,生产出产品的批量使用证明,焊接质量完全满足使用要求。     

Dentin penetration of 2 calcium hydroxide combinations

OBJECTIVE: Calcium hydroxide is a common intracanal medicament. The powder can be mixed with different vehicles for placement in canals. This study examines pH changes in dentin with 2 different calcium hydroxide preparations. STUDY DESIGN: The combinations used were calcium hydroxide + distilled water and calcium hydroxide + glycerin (1/7 distilled water). One hundred forty extracted teeth with single canals were used. pH changes in dentin after the intracanal placement of these combinations were evaluated at different dentin thicknesses by measuring the pH of the external environment. RESULTS: For all dentin thicknesses and at all time periods, the calcium hydroxide + glycerin combination showed significantly higher pH values than the calcium hydroxide + distilled water combination. CONCLUSIONS: Considering pH elevations, we propose the use of a calcium hydroxide + glycerin combination.     

实验室信息管理系统在太钢的应用

介绍了实验室管理系统的流程、主要模块、功能和运行效果。通过实施该系统,将实验室的业务流程、资源有机地结合起来,采用现代网络技术、数据库和标准化的实验室管理思想,组成一个规范的管理体系,实现了对样品检测流程、实验室资源、记录及报告等要素的综合管理,为实验室内部管理与对外连接提供了信息平台。     

Laboratory Tests of Cable-Based Roof Moisture Detection System

The writers have devised a prototype cable-based roof moisture detection and location system (U.S. Patent 5,648,724) that was tested in simulated conditions. The detection system can use a variety of principles to monitor roofing for the presence of moisture. The location system uses a metallic time-domain reflectometer (MTDR) to locate a suspected wet area by sending an electromagnetic pulse or step signal down the sensor cable and looking for reflections caused by a change in the dielectric constant surrounding the cable due to the presence of a wet area. Tests revealed the MTDR technique to be sensitive and able to locate the position of less than 1 L (0.22 gal.) of water within 0.3 m (1 ft) over 30.5 m (100 ft) of cable. Where multiple regions of wetting were present along the length of the cable, it was possible to locate each boundary between wet and dry.     

金属材料累积叠轧焊界面的结合特性

 金属材料的界面结合特性是累积叠轧焊技术的关键,在多功能强力热轧机上利用ARB工艺分别对Q235钢和L2纯铝进行了累积叠轧焊自身界面结合特性的试验研究。重点研究了累积叠轧焊材料的界面结合特性,界面结合强度,界面断裂特性,材料组织状态对界面结合的影响。研究结果表明：材料的界面结合性能不仅与首次压下量、变形温度有关,而且,在再结晶温度以下,累积叠轧次数与首次临界变形量共同决定了材料的显微结构,从而决定了材料的界面结合特性,当累积次数超过2次时,材料的界面结合接近基体强度。