苯胺衍生物掺杂的PMMA薄膜的二次非线性光学性能的稳定性研究

具有A-π-D电子结构的苯胺衍生物掺杂的玻璃态高聚物PMMA的有机薄膜经极化取向后显示很强的二次非线性光学性能,其取向弛豫是实用化的一个有待解决的重要问题。木文通过几种苯胺衍生物以不同百分比与PMMA掺杂,用紫外-可见吸收光谱、二次谐波强度测量、动态力学粘弹谱等方法进行了取向弛豫的机理研究,结果表明分子尺寸和形状以及偶极矩的大小对取向弛豫有显著影响。     

超细α-FeOOH制备过程研究 Ⅰ.制备工艺

以制备晶形、粒度、轴比等满足高性能磁粉要求的铁黄为目标,研究了碱法超细α-FeOOH合成的工艺配方和工艺条件对粒子性能的影响,包括碱比、气量、转速、Fe(OH)_2结晶条件、熟化时间等工艺参数的影响规律。重复稳定地制备出三类超微粒α-FeOOH粒子,其粒度分别为0.18、0.28、0.39μm,分布均匀,无枝叉。     

医用低值材料采供管理的探讨

医疗消耗材料是医疗工作开展的基础，本文从医用低值消耗材料的计划制定、材料采购、库房库存结构、材料供应、成本核算等多方面探讨了如何对医疗消耗材料进行科学管理，这对医院的医疗发展和管理建设有着重要意义。     

Industrial back belts and low back pain: Mechanisms and outcomes

The recent increased utilization of industrial back belts as personal protective equipment in the workplace has generated considerable controversy among occupational health and safety professionals in the United States. The purpose of this article is to review the literature regarding proposed mechanisms of action of these devices and studies related to outcome of belt utilization in the prevention of low back pain and disability in the workplace. At the present time, neither the suspected mechanisms of action nor the efficacy of these devices in the primary, secondary, and tertiary prevention of work-related low back pain has been adequately demonstrated in clinical trials. As a result, generally accepted guidelines regarding the safe use of belts in the occupational setting have not been established. Based on this review it is recommended that further well-controlled, prospective, randomized clinical trials are necessary to evaluate the effectiveness of these devices as personal protective equipment. During the interim, the decision to prescribe belts to employees in the workplace should be at the discretion of an adequately trained occupational health care provider. These devices should not be provided as an alternative to appropriate administrative and/or engineering controls.     

A flexible, efficient, checkerboard immunoblot system for the detection and semiquantitation of specific antinuclear antibodies.

In this paper an uncomplicated method for the simultaneous detection and semiquantitation of 11 of the 12 commonly studied antinuclear antibodies (ANA) in a single run is described. This new application of checkerboard immunoblotting (CBIB) is based upon available technology and employs purified antigens which can be either purchased or produced in-house. CBIB requires no electronic instrument, can be formatted to meet the needs of the user, is rapidly performed, and has acceptable labor and materials costs. Data on the use of the method to examine available reference antisera is presented. CBIB has also proven practical for the clinical study of 18 sera, at two dilutions per membrane, for each set of specific antinuclear antibodies, also at two or more dilutions.     

Safety evaluation of surgical materials by cytotoxicity testing

The cytotoxicity of three kinds of commercially available absorbable hemostats [oxidized cellulose (Surgicel, gauze and cotton types), microfibrillar collagen (Avitene), and cotton-type collagen (Integran)] and one adhesion barrier [sodium hyaluronate and carboxymethyl-cellulose membrane (Seprafilm)] were comparatively assessed by a colony assay using V79 cells and a minimum essential medium (MEM) elution assay in combination with a neutral red assay using L929 cells. Strong cytotoxicity was detected for Surgicel by both the MEM elution assay and the colony assay. For Avitene, both methods revealed weak cytotoxicity. For Seprafilm, no cytotoxicity was detected by the MEM elution assay, while a moderate degree of cytotoxicity was observed in the colony assay. For Integran cytotoxicity was not detected by either the MEM elution or the colony assay. The results of the different methods showed some inconsistency in terms of the degree of cytotoxicity of the materials. It is proposed that the combination of two or more sensitive cytotoxicity testing methods for the evaluation of biomaterials is necessary to avoid false-negative results for biomaterials at the preclinical stage. Furthermore, investigation of the correlation between the cytotoxicity and the extraction period of the surgical materials is helpful for predicting the effect of prolonged in vivo use of biomaterials on surrounding cells, tissues, and organs.     

聚合色素膜的极化及二次谐波产生的研究

对键合偶氮染料的聚合素薄膜，进行分子二阶非线性光学性能测定，结果表明：极化时间、温度及电场强度等因素对二次谐波的产生具有显著的影响。本实验中，极化时间以２０－３０ｍｉｎ，极化温度在该聚合物的Ｔｇ附近，极化电压以５ＫＶ为宜。比较了聚合色素与染料－聚合物掺杂系统两种情况下，二次谐波随时间的变化，结果是前者比后者具有更高的稳定性。可见，聚合色素膜比掺杂系统更有希望成为实用化的非线性光学材料。     

胆道支撑管显影材料的制备及体外细胞毒性评价

目的 探讨新型显影胆道支撑管材料制备的可行性，对构建出的材料进行体外细胞毒性评价和筛选。方法 选择具有X线下显影特性的基础材料A、B、C，分别与硅橡胶生胶共混炼，模压后分别得到相应的显影复合材料甲、乙、丙，经一段和二段硫化过程完成加工。采用MTT法作为体外细胞毒性评价的方法，测定参比对照材料和新材料的50％浓度的浸提液对小鼠成纤维细胞的增殖率的影响，确定细胞毒性级别。结果 新材料甲、乙、丙在x线下影像清晰。甲、乙材料的细胞毒性级别为零，丙材料细胞毒性级别为2。结论 构建出在X线下显影的弹性体材料可行。材料甲、乙是制造新型胆道支撑管的初选材料，材料丙无应用的价值。     

Transport of urea and amino acids through the isolated human placenta

By means of a method of two-way perfusion of the isolated human placenta the transport of urea from the fetal to the maternal placental circulation and the transport of amino acids in the opposite direction were studied. Experiments showed that the method provides for sufficiently complete perfusion of the intervillous space and creates suitable conditions for the study of placental transport. If the amino nitrogen concentrations in the two circulatory systems are equal, its concentration in the fetal circulation rises in the course of the experiment. On the addition of an amino acid to the maternal circulation, this increase develops to a greater degree. The results of these experiments confirm the view that amino acids are secreted by trophoblast cells into the fetal circulation.Laboratory of Biochemistry, Institute of Obstetrics and Gynecology, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR M. A. Petrov-Maslakov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 4, pp. 394–397, April, 1976     

基于骨和无有机成分骨与羟基磷灰石压缩性能实验比较的强度分析

目的分析判定以珊瑚为基体,通过水热交换法制成的羟基磷灰石植入体内后的强度是否可以达到活体骨的水平。方法实验测量羟基磷灰石、含有机成分的骨、无有机成分的骨的压缩极限应力。通过对比羟基磷灰石、骨及无有机成分的骨的压缩强度差别,确定胶原纤维对骨压缩强度的作用,进而应用经验模型预估人造羟基磷灰石在一定空隙度(0.1～0.5)范围变化时的强度。结果羟基磷灰石、骨及无有机成分的压缩强度分别为14.1 GPa、207 GPa和31.7 GPa。结论去除骨中的有机成分后其压缩强度降低约80%。水热交换法制成的羟基磷灰石抗压强度可能高于骨内羟基磷灰石,这种骨替代材料植入体内后,随着骨和纤维组织在内部生长,其强度有可能达到活体骨的水平。