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41.
42.
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。 相似文献
43.
本文通过对多台日本光电公司遥测心电监护仪ZB-313P发射盒发射和接收石英晶体振荡器频率的实际测试以及对测试结果数据的分析研究。了解和掌握了其内在的规律,推导出了该发射盒的标称频率,实际发射频率以及监护仪接收频率三者之间关系变化的计算公式,以此公式计算出来的频率数据。可作为采用国产石英晶体振荡器对日本光电该系列监护仪进行维修的依据。并为此类设备的维修应用提供了一定的指导作用。 相似文献
44.
单向中频电加助透液防治瘢痕增生 总被引:6,自引:0,他引:6
为防治瘢痕增生,寻求有效治疗方法,我们采用单向中频电加助透液治疗瘢痕增生患者33例,痊愈显效率为64%,总有效率为88%。结果表明,单向中频电加助透液能增强导入作用,是防治瘢痕增生的有效方法。 相似文献
45.
用放射免疫法测定产后40天和60天乳母血清泌乳素基础水平和吸吮后泌乳素最大反应性增值,发现其与乳母泌乳量、婴儿吸吮频率、吸吮时间之间均不存在正相关关系,推测引起泌乳素分泌除吸吮外,还存在其他机理。 相似文献
46.
Eight premature babies affected by hyaline membrane disease and needing mechanical respiratory support were ventilated by means of a VDR 1 (Bird Space Technology) respirator at 10 Hz during a mean time of 51 h. Before HFV 7 infants had been on conventional mechanical ventilation (CMV) and one on nasal CPAP. The values of mean airway pressure (MAP) and oxygenation index (PaO2/FIO2) on CMV and HFV were (mean and range): 1. CMV: MAP 15 (4–29) mm Hg, ox. index 15.47 (5.07–23.19) kPa; 2. HFV after 1 h: MAP 15 (10–19) mm Hg, ox. index 24.13 (9.07–46.12) kPa. Improved oxygenation allowed rapid reduction of FIO2 in the following hours. Only 3 infants were weaned directly from VDR 1, 5 were switched back to CMV mainly because of technical failures of the respirator. The change from HFV to CMV was associated with a fall of PaO2/FIO2 from 35.99 (15.86–74.52) to 22.39 (7.33–31.46) kPa. The mean time of artificial ventilation (CMV+HFV) was 121 h (range 46–166). Except for 1 pneumothorax no medical complications were seen during HFV, and all patients survived. Despite impressive improvements in oxygenation it is cautioned against the use of the VDR 1 because of the high incidence of technical problems. 相似文献
47.
Comparison of the haemodynamic effects of intermittent positive pressure ventilation with high frequency jet ventilation 总被引:1,自引:0,他引:1
The cardiorespiratory effects of intermittent positive pressure ventilation and high frequency jet ventilation with and without positive end expiratory pressure were compared in patients following valvular heart surgery (mitral and/or aortic). Twenty patients received intermittent positive pressure ventilation and high frequency jet ventilation with 0, 0.5 and 1.0 kPa positive end expiratory pressure. High frequency jet ventilation was well tolerated. The addition of 1.0 kPa positive end expiratory pressure was associated with preservation of the arterial oxygen tension without any increase in shunt or significant adverse haemodynamic effect. The results are discussed and compared with a previous study of high frequency jet ventilation following aortocoronary bypass graft surgery. 相似文献
48.
利用TiCl4+O2体系,在高频等离子体化学气相淀积反应器中合成了纯度高、粒度细的TiO2粒子。考察了工艺条件对TiO2粒子物性的影响;探讨了TiO2粒子晶型控制的方法,金红石型质量分数可通过工艺条件控制;探讨了TiO2粒子晶型控制的方法。金红石型质量分数可通过工艺条件控制,减少TiO2单体浓度可提高金红石型质量分数;也可通过在原料TiCl4中添加AlCl3等晶型转化剂,使可转化为单一金红石型Ti 相似文献
49.
我院抗菌药物用药调查与分析 总被引:8,自引:0,他引:8
本文统计了1990年和1993年抗菌药物购药金额、数量、DDD值,计算DDD数及每日治疗费用,将总购入量、DDD值、DDD数及金额数进行排序,求出金额数序号与DDD数序号的比值,从中了解全院抗菌药用药频度。本文调查结果认为在本院使用的第三代头孢类抗生素所占金额比重极大,在DDD数排序中,居前10位的头孢类是第一代头孢,喹诺酮类用药频度逐年提高。 相似文献
50.
P. Hammond C. J. D. Pomfrett 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1991,85(3):631-640
Summary Spatial-frequency dependence of directional tuning and directional bias was compared, for both eyes, in four previously established discrete classes of binocular feline striate cortical neurones. Two classes (respectively direction-selective or bidirectional at optimal spatial frequency) were directionality invariant at all spatial frequencies. In the remaining two classes, both directionbiased at optimal spatial frequency, directional bias either altered or reversed with change in spatial frequency. In all four classes, the directional tuning of a majority of neurones sharpened at high spatial frequency through either eye, although the bandpass characteristics were sometimes dissimilar for the two eyes. All neurones were of the same type through either eye. Amongst the two classes of direction-biased neurones, the strength of bias was commonly different through the two eyes. Where reversal of bias occurred, that reversal took place at different spatial frequencies for each eye. Thus, the direction and orientation preferences of cortical neurones are fixed at optimal spatial frequency, but their envelope of tuning to a gamut of spatial frequencies is not. These differences are potentially related to binocular coding of visual perspective, including dynamic object rotation in visual space. 相似文献