紫外线对两种聚四氟乙烯电荷储存稳定性的影响

利用在室温下的栅控恒压电晕充电后经不同强度紫外线辐照的表面电位测量,研究了紫外线对聚四氟乙烯(polytetrafluoroethylene,PTFE)多孔膜、聚四氟乙烯非多孔膜驻极体电荷储存稳定性的影响,探讨了两种聚四氟乙烯驻极体医疗产品使用紫外消毒方法的可行性.结果:(1)在常温条件下,紫外线辐照对两种聚四氟乙烯驻极体的电荷储存稳定性的影响不大;(2)聚四氟乙烯多孔膜驻极体的电荷储存能力随环境湿度的提高而略有下降;(3)聚四氟乙烯医用驻极体产品可采用紫外消毒法消毒.     

A new physical assay method for tobacco mosaic virus using a radioactive virus recovery standard and the first derivative of the ultraviolet absorption spectrum

A new physical assay method for tobacco mosaic virus is described which incorporates two improvements on previous procedures. Losses of up to 75% of virus during extraction are corrected by adding a trace of radioactive virus to leaf samples before homogenization, and determining percentage recovery of radioactivity in final virus preparations. Estimation of virus concentration in partially purified preparations is from the first derivative (dA/d lambda) of the ultraviolet absorption spectrum, using a pronounced signal from the tryptophan fine-structure absorption band at 285-293 nm. This method is highly insensitive to ultraviolet-absorbing contaminants, which cause errors and increase variation between replicates, when estimation of virus concentration is by normal measurement of ultraviolet absorption (A260). The method can be applied to at least some other viruses.     

Conjugation of DNA fragments to protein carriers by glutaraldehyde: immunogenicity of oligonucleotide-hemocyanin conjugates

The practical realization of the concept of specific immunotherapy for systemic lupus erythematosus (SLE) has been hampered, thus far, by an inability to link DNA fragments to carrier protein. In this paper, a novel technique is described, in which glutaraldehyde is the linking agent. A 2-stage method was used to link oligonucleotides to a soluble protein carrier, such as keyhole limpet hemocyanin (KLH) or human gamma globulin (HGG), whereas a 1-stage technique was sufficient to link oligonucleotides to sheep red cells. Both the ultraviolet absorbance spectrum and diphenylamine assay demonstrated that oligonucleotides were coupled to soluble protein. The conjugate of oligonucleotide to protein carrier appears to be recognized by anti-DNA antibody since oligonucleotide linked to either KLH or HGG inhibited the binding of anti-DNA antibody in vitro, and oligonucleotide-coupled sheep cells are agglutinating by seropositve sera from lupus patients. In addition, oligonucleotide-KLH raised hemagglutinating antibody to denatured DNA in C57BL/6, DBA/2 or NZB mice, as well as IgG antibody as detected by SPRIA in C57BL/6 and DBA/2 mice. The significance of this new method for the development of an antigen specific therapy of SLE is discussed.     

Environmental conditions and variation in levels of sun exposure among children in child care

Sun exposure in childhood is 1 of the risk factors for developing skin cancer, yet little is known about levels of exposure at this age. This is particularly important in countries with high levels of ultraviolet radiation (UVR) such as Australia. Among 49 children 3 to 5 years of age attending child care centers, UVR exposure was studied under 4 conditions in a repeated measures design; sunny days, cloudy days, teacher’s instruction to stay in the shade, and a health professionals instruction to apply sunscreen. Three different data collection methods were employed: (a) completion of questionnaire or diary by parents and researcher, (b) polysulphone dosimeter readings, and (c) observational audits (video recording). Results of this study indicated that more than half the children had been sunburnt (pink or red) and more than a third had experienced painful sunburn (sore or tender) in the last summer. Most wore short sleeve shirts, short skirts or shorts and cap, that do not provide optimal levels of skin protection. However, sunscreen was applied to all exposed parts before the children went out to the playground. Over the period of 1 hr (9–10 a.m.) the average amount of time children spent in full sun was 22 min. On sunny days there was more variation across children in the amount of sun exposure received. While the potential amount of UVR exposure for young children during the hour they were outside on a sunny day was 1.45 MED (Minimum Erythemal Dose), they received on average 0.35 MED, which is an insufficient amount to result in an erythemal response on fair skin even without the use of sunscreen.     

真空紫外辐照对加成型硅橡胶光学性能的影响

考察了加成型硅橡胶在真空环境中经1000ESH紫外辐照后的性能变化。结果表明,辐照后材料均出现发黄的现象,光学透过率大幅度 下降,同时加入硅酸钾包覆后制备的热控涂层反射率下降。经原位测试与离位测试,发现加成型硅橡胶在两种不同条件下测得的结果差异较小,而在有机硅橡胶中加入ZnO后原位与离位测试结果则差异明显,表现出明显的漂白作用。     

Expression of P53 during lens epithelial cell apoptosis induced by ultraviolet

Cataract is a disease induced by multi- factorsand its pathologic mechanism isstill unknown.Ithasbeen accepted that ultraviolet irradiation ( UVR) isone of the most important pathogenesis.Li etal hasreported that UVR could induce the apoptosis of lensepithelial cells( LECs) and resulted in lens opacities.In order to study the pathologic mechanism of UVR-induced cataract at molecular and cellular levels,weinvestigated the apoptosisof LECs and the expressionof P5 3.1　 MATERIALSAND M…     

Ultraviolet blood irradiation and oxygenation affects free radicals and antioxidase after rabbit spinal cord injury

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红外线短波紫外线照射对感染伤口愈合的影响

目的：探讨红外线、短波紫外线照射对感染性伤口愈合的影响。方法：用随机方法将７２例感染伤口病人分为Ａ、Ｂ两组,每组３６例,Ａ为治疗组：在消炎、伤口换药基础上加用红外线、短波紫外线照射伤口７天,Ｂ为对照组：单纯消炎、伤口换药。结果：Ａ组治愈２８例,显效８例,有效率１００％。Ｂ组治愈１４例,显效１２例,无效１０例,有效率７２％,统计学处理Ｘ＾２＝１５．４７Ｐ〈０．０１,两组有显著差异。结论：红外线、短波     

二氧二茂钛原料药的稳定性研究

利用紫外分光光度计对二氯二茂钛进行含量测定。回归方程为 :Y =0 9881X - 0 90 90× 10 -3(Y :吸光度 ;X :浓度 ,mg/L) ,相关系数r=0 9999,线性范围为 13 .6～ 81.6mg/L。模拟试验 3份 ,回收率为 98 4 5 %～ 10 1 3 3 % ,相对标准偏差为 0 14 %～ 0 3 3 %。本实验研究了原料药二氯二茂钛的稳定性 ,结果表明不同的湿度、温度等条件对二氯二茂钛的稳定性有一定影响     

紫外分光光度法测定甲磺酸酚妥拉明片的含量

目的 采用紫外分光光度法测定甲磺酸酚妥拉明的含量。方法 紫外分光光度法,检测波长２７８nm。结果 甲磺酸酚 妥拉明浓度在８．０～３３．０mg/Ｌ范围内,浓度与吸收度 呈良好的线性关系;r＝０．９９９ ９,n＝７,平均回收率为９９．７％。结论该方法简单、快速、精确、重现性好。