Cyclic tensile stretch load and oxidized low density lipoprotein synergistically induce lectin-like oxidized ldl receptor-1 in cultured bovine chondrocytes, resulting in decreased cell viability and proteoglycan synthesis.

Mechanical stimulation is known to be an essential factor in the regulation of cartilage metabolism. We tested the hypothesis that expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) can be modulated by cyclic tensile stretch load in chondrocytes. Cyclic loading of repeated stretch stress at 10 cycles per minute with 10 kPa of stress for 6 h induced expression of LOX-1 to 2.6 times control in cultured bovine articular chondrocytes, equivalent to the addition of 10 microg/mL oxidized low density lipoprotein (ox-LDL) (2.4 times control). Application of the cyclic load to the chondrocytes along with 10 microg/mL ox-LDL resulted in synergistically increased LOX-1 expression to 6.3 times control. Individual application of cyclic loading and 10 microg/mL ox-LDL significantly suppressed chondrocytes viability (84.6% +/- 3.4% and 80.9% +/- 3.2% of control at 24 h, respectively; n = 3; p < 0.05) and proteoglycan synthesis [81.0% +/- 7.1% and 85.7% +/- 5.2% of control at 24 h, respectively; p < 0.05 when compared with 94.6% +/- 4.6% for native-LDL (n = 3)]. Cyclic loading and 10 microg/mL ox-LDL synergistically affected cell viability and proteoglycan synthesis, which were significantly suppressed to 45.6% +/- 4.9% and 48.7% +/- 6.7% of control at 24 h, respectively (n = 3; p < 0.01 when compared with individual application of cyclic loading or 10 microg/mL ox-LDL). In this study, we demonstrated synergistic effects of cyclic tensile stretch load and ox-LDL on cell viability and proteoglycan synthesis in chondrocytes, which may be mediated through enhanced expression of LOX-1 and which has important implications in the progression of cartilage degeneration in osteoarthritis.     

Indoor radon measurement with The Lucas cell technique

Rn-222 is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the Rn-222 progeny, especially in closed atmospheres. A Lucas cell technique, using a portable device, “PRASSI” (SILENA mod. 5S), for Rn-222 measurements inside the Centre for Radiation Protection and Radioecology (ZSR), Hannover University was used. The portable radon monitor PRASSI is suitable for radon gas continuous or grab sampling measurements with the scintillation cell technique. In recognition of the wide periodic variations in concentration, measurements were made daily for extended periods. At the same time, meteorological variables, such as temperature and humidity were observed so that their influence on radon levels could be evaluated. The radon average concentration during the year was about 55.9 Bq/m³ which gives rise to an annual effective dose 2.2 mSv y⁻¹. The radon concentration is within the limits prescribed by the International Commission for Radiation Protection. A detailed analysis of radon distribution with seasonal variation is presented.     

直线加速器十年故障分析总结

目的分析和总直线加速器十多年来的故障。方法根据十多年来的故障维修记录，统计和分析直线加速器各阶故障率及故障特点。结果直线加速器使用早期由于机器不稳定故障率比较高，使用中期及其比较稳定，故障率比较低，使用后期由于零部件老化，故障率比较高。     

Notes on the use of low magnification telescopes in low vision care

Several areas related to the use of telescopes in low vision are reviewed. These include: contrast sensitivity function; eccentric viewing through a telescope; field of view; telescope used in reverse; and IOL-spectacle lens telescopic systems. Experimental data are included to support selected clinical observations routinely made by low vision clinicians.     

安徽省X射线诊断受检者剂量水平调查

目的　了解安徽省X射线诊断受检者体表剂量水平。方法　体表剂量监测按国家标准 ,采用热释光剂量计。结果　胸部摄片受检者的体表剂量最低 ,为 0 .39～ 0 .5 3mGy ,比胸部透视平均体表剂量减少 88.6 6 %。结论　减少或控制透视比例 ,降低受检者群体的体表剂量 ,以减少医疗照射对人体造成的危害。     

控制性降压在临床麻醉中的应用进展

控制性低血压是指在某些手术麻醉期间，用药物等方法降低血压，以达到减少手术野出血，便于手术操作的一种方法，通常采用血管扩张剂，钙通道阻断剂及麻醉来控制血压，现就这一领域的研究进展作一综述。     

极低频强磁场对豚鼠听阈的影响

本研究以豚鼠皮层听觉诱发电位反应阈为指标，采用自体或群体对照方法，观察０．１Ｈｚ极低频磁场对豚鼠听力的影响。结果表明，豚鼠经５０ｍＴ（毫特）、４ｈ，１００ｍＴ、４８ｈ及１０ｍＴ、４周暴露后，听阈降低；５０ｍＴ、４８ｈ，２０ｍＴ、４周暴露后听阈无明显变化。提示０．１Ｈｚ极低频磁场对豚鼠听敏度无不利的影响，在某些暴露条件下，听敏度尚有改善。     

周围剂量当量仪的研制

周围剂量当量仪研制是根据国际辐射单位和测量委员会（ＩＣＲＵ）３９号报告推荐的周围剂量当量而设计的一种数字化智能型辐射防护仪。方法采用能量补偿对探测器进行能响校正。结果补偿结果使得探测器在４７～２３０ｋｅＶ与ＩＳＯ推荐的Ｈ＊（１０）／Ｋａ值误差在５％以内。本文重点描述了周围剂量当量仪探测器部分的工艺结构和剂量学性能以及电子学测量部分的主要功能。结论通过实际应用我们初步获得的结论是由于该仪器可直接测量周围剂量当量，稳定性好且具有自动取平均值特点，它可做为实验室校准用测量仪器，又由于该仪器体积小，电池供电，读数面板又有背光功能，它也可以做为现场仪器用于辐射防护实践的现场测量