强噪声暴露对大鼠急慢性胃粘膜损伤的影响

目的观察强噪声暴露对大鼠急慢性胃粘膜损伤的影响。方法急性实验用Ｗｉｓｔａｒ大鼠２０只,随机分为两组,每组１０只。实验组每天给连续６小时强噪声刺激,对照组无噪声刺激;３天后均经口灌注０．８ｍｏｌ／Ｌ盐酸１ｍｌ,观察胃粘膜损伤变化。慢性实验选Ｗｉｓｔａｒ大鼠３６只,均制作胃溃疡模型,实验组１８只,术后给强噪声刺激每天６小时,对照组１８只无噪声刺激;观察两组实验第１０天和第４０天时的大鼠胃溃疡面积。结果经强噪声暴露再灌注盐酸后大鼠胃粘膜损伤指数为１８２．８０±６１．３２,较对照组的６９４．７０±１８３．０２有非常显著性差异（Ｐ＜０．０００１）。慢性胃溃疡模型术后给强噪声暴露第１０天和第４０天的大鼠溃疡面积各与其对照组比较明显为大,均有显著性差异（Ｐ＜０．０５）。结论强噪声暴露对大鼠急性胃粘膜损伤及慢性胃溃疡愈合有明显负性影响     

船舶噪声对豚鼠耳蜗微音电位响应曲线的影响

在排除电场干扰伪迹后，耳蜗微音电位响应曲线可以作为反映近全耳蜗电生理功能的一项测试指标。能方便而迅速地完成测试，结果可靠。船舶噪声暴露后，显示耳蜗损伤频带主要在３．１５～８ｋＨｚ范围。这与人噪声性听力损失的特征非常类似。     

γ射线与噪声对豚鼠听觉损伤的复合效应

研究了γ射线（２０Ｇｙ）与噪声（１０５ｄＢＡ，３０ｍｉｎ）一次联合作用及６次重复联合作用（每次γ射线０．６７Ｇｙ，噪声１００ｄＢＡ，３０ｍｉｎ），对豚鼠听觉损伤的复合效应。结果表明，先γ射线２０Ｇｙ照射后噪声暴露对听觉损伤的复合效应是协同的。６次重复联合作用时，先噪声暴露后照射组的听阈偏移小于先照射后噪声暴露组；前者的复合效应为拮抗，后者为相加。本文对γ射线与噪声对听觉损伤联合作用的机理作了初步探讨。     

In vivo comparison of two through-plane MR velocity mapping methods: Fast fourier encoding and phase mapping

Magnetic resonance imaging maps of velocity were acquired with a 1.5-T system in 10 subjects in a plane perpendicular to the main pulmonary artery. Velocity images were successively acquired with a method developed from Fourier-encoding velocity imaging (FEVI) principles with eight gradient steps and one excitation, and with two-point phase-subtraction mapping. Reconstruction in FEVI was implemented by zero-filling interpolation around the eight gradient steps and then around the four central steps. The methods were compared by using estimates of noise in velocity measurements based on the difference between the experimental map and a smooth fitted map. For the same acquisition time, FEVI with four encoding steps was more precise in velocity measurements than phase mapping. Precision was further increased by the use of eight encoding steps, but acquisition time was doubled.     

64层螺旋CT心脏成像获得一致噪声及控制辐射剂量的个体化管电流选择方法

目的 探讨根据患者个体差异调整管电流(mA),获得一致64层螺旋CT冠状动脉血管成像(CTCA)的图像噪声,进而控制辐射剂量的方法.方法 (1)80例患者作为固定mA组(650 mA)以一致的扫描条件进行64层螺旋CTCA检查.2名医师用5分法评价固定mA组的噪声水平以确定诊断图像质量所需要的噪声水平标准差(SD)SD.值,并建立一个少量对比剂团注探测循环时间扫描(TB)噪声SDTB值和心脏扫描(CA)达到SD0水平所需mA的关系式.(2)80例64层螺旋CTCA检查根据个体差异调整扫描mA,作为个体mA调制组与固定mA组进行比较,分析该方法的可操作性和辐射剂量的控制,两组均数比较用独立样本t检验.结果 (1)固定mA组的TB和CA的噪声SD呈线性相关(r2=0.994);(2)根据主观评价的结果将SD0定为28 HU可获得满意的图像质量;(3)个体mA调制组噪声平均值28.97 HU,SD为1.93,小于固定mA组的5.14,但质量评分(4.27±0.68)与固定mA组(4.03±0.93)差异无统计学意义(P＞0.05);(4)个体mA调制组63例调整后＜650 mA,平均CT剂量指数(CTDIvol)为58.32 mGy,比固定mA组(85.94 mGy)减少了32.1%,其中1例患者仪使用160 mA,CTDIvol=19.27 mGy,是固定mA组平均剂量的22.4%.结论 通过个体的TB噪声SD调整mA可获得一致心脏扫描噪声水平,是有效的实用的保证成像质量又对个体辐射剂量进行控制的方法.     

Noise pollution on an acute surgical ward

INTRODUCTION

This study was undertaken to measure and analyse noise levels over a 24-h period on five general surgical wards.

PATIENTS AND METHODS

Noise levels were measured on three wards with four bays of six beds each (wards A, B and C), one ward of side-rooms only (ward D) and a surgical high dependency unit (ward E) of eight beds. Noise levels were measured for 15 min at 4-hourly intervals over a period of 24 h midweek. The maximum sound pressure level, baseline sound pressure level and the equivalent continuous level (LEq) were recorded. Peak levels and LEq were compared with World Health Organization (WHO) guidelines for community noise. Control measurements were taken elsewhere in the hospital and at a variety of public places for comparison.

RESULTS

The highest peak noise level recorded was 95.6 dB on ward E, a level comparable to a heavy truck. This exceeded all control peak readings except that recorded at the bus stop. Peak readings frequently exceeded 80 dB during the day on all wards. Each ward had at least one measurement which exceeded the peak sound level of 82.5 dB recorded in the supermarket. The highest peak measurements on wards A, B, C and E also exceeded peak readings at the hospital main entrance (83.4 dB) and coffee shop (83.4 dB). Ward E had the highest mean peak reading during the day and at night – 83.45 dB and 81.0 dB, respectively. Ward D, the ward of side-rooms, had the lowest day-time mean LEq (55.9 dB). Analysis of the LEq results showed that readings on ward E were significantly higher than readings on wards A, B and C as a group (P = 0.001). LEq readings on ward E were also significantly higher than readings on ward D (P < 0.001). Day and night levels differ significantly, but least so on the high dependency unit.

CONCLUSIONS

The WHO guidelines state that noise levels on wards should not exceed 30 dB LEq (day and night) and that peak noise levels at night should not exceed 40 dB. Our results exceed these guidelines at all times. It is likely that these findings will translate to other hospitals. Urgent measures are needed to rectify this.     

手术室噪音对病人生理心理影响及护理探讨

目的探讨手术室噪音对病人生理心理的影响,并提出相应的护理措施。方法选择在我院实施非全麻手术病人80例,随机分为实验组和对照组。实验组在手术中采取降噪措施,对照组对手术室噪音未加任何控制。比较两组病人的心率、血压、焦虑水平和伤口拆线时间。结果实验组心率和血压明显低于对照组(P<0.05);术后实验组和对照组焦虑发生率分别为40.0%、70.0%,差异有统计学意义(P<0.05),而两组术前焦虑程度无明显差别(P>0.05);实验组病人伤口拆线时间比对照组明显缩短(P<0.05)。结论应采取多种措施降低手术室噪音,为病人建立一个安全、舒适的治疗环境。