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In this paper we presented the effect of breathing oxygen at 2 atm or 1 atm before or after exposure on noise-induced hearing damage.The noise exposure was made with a 1/3 octave bandnoise(1000 Hz,136 dB,1 hour).The inhalation of 2 atm-oxygen before or after exposure couldreduce noise-induced permanent threshold shift.The role of breathing 2 atm-oxygen correspondedto reduce the noise level by 10 dB.The effect of prophylactic inhalation of oxygen was much betterthan that of therapeutic inhalation of oxygen,and the effect was better at 2 atm than at 1 atm.Somemechanisms concerning inhalation of hyperbaric or high concentration oxygen were discusscd inprevention and treament of noise-induced hearing damage. 相似文献
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以乙醇为溶剂,在低温条件下合成出了两种手性硼磷酸盐化合物BaBPO5(1)(T=120℃,t=5d)和(H3O)Zn(H2O)2BP2O8·H2O (2)(T=80℃,t=5d).XRD单晶衍射仪测定了化合物的结构,结果表明:(1)属三方晶系,P3221空间群,a=b=7.1162(3)(A),c=6.9979(6),(A)=3,该晶体含有一维线性链状阴离子结构;(2)属六方晶系,P6122空间群,a=b =9.513(2)(A),c=15.906(8),(A)=6.该晶体具有三维骨架结构.实验结果表明使用乙醇作溶剂可以极大降低硼磷酸盐的合成温度,进而有助于获得手性硼磷酸盐化合物,这为手性硼磷酸盐的合成提供了一种新思路. 相似文献
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本文报道豚鼠在噪声暴露前后吸2atm或latm纯氧对噪声性听觉损伤的影响。暴露噪声是1/3oct窄带噪声,中心频率1000Hz,强度136dB作用1h。在噪声暴露前或暴露后吸2atm纯氧可以减小噪声引起的永久性听阈偏移(对短声)。吸2atm纯氧所起的作用(预防吸氧一次或治疗吸氧六次,每次1h),相当于把噪声强度降低1OdB(从136dB降至126dB。预防吸氧(暴露前吸氧)比治疗吸氧(暴露后吸氧)效果好。吸2atm纯氧比latm有效。文中讨论了吸高压氧或高浓度氧在预防和治疗噪声性听觉损伤中的某些机理。 相似文献
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