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101.
Emulsions (o/w) were prepared from solid-state emulsions comprised of various matrix materials and oils and the resultant particle size properties determined. Results suggest that for those matrices that can form solid-state emulsions, the droplet size decreased as a function of time, as previously observed. The final droplet size was dependent on the oil utilized but was independent of the matrix material. The use of mineral oil resulted in the smallest droplet diameter (1.5 µm) while isopropyl myristate resulted in the largest droplet diameter (3 µm). With the exception of mineral oil, the oil/water interfacial tension was found to be directly proportional to the droplet diameter. The rate of emulsification appeared to be bi-phasic. The initial emulsification phase appeared to be independent of the matrix material while the terminal phase was a function of the matrix material. Most importantly, it was found that solid state emulsions could be prepared from a diverse, yet specific, list of matrices.  相似文献   
102.
The pattern electroretinogram and the visual evoked potential were recorded simultaneously with various stimulus fields and artificial scotomata of increasing sizes. In contrast to an earlier study, a smaller check size (20) and two stimulus field sizes (20° × 20° and 10° × 10°) for the scotomata were used. With a concentric decreasing stimulus field, a reduction of both the pattern electroretinogram and visual evoked potential was found. Both showed a simultaneous reduction of amplitudes, but, compared with the amplitude in the full field, the reduction was more extensive for the pattern electroretinogram at each test field size. This implies a greater contribution to the pattern electroretinogram from more eccentric retinal parts. An artificial central scotoma of increasing size in the 20° × 20° field had less influence on the pattern electroretinogram than on the visual evoked potential. The percentage amplitude loss of the visual evoked potential was more pronounced. The visual evoked potential was eventually abolished by a scotoma size from 10° × 10° upward, while the pattern electroretinogram was still registrable. When scotomata of similar size were introduced in a smaller (10° × 10°) field, percentage pattern electroretinogram and visual evoked potential amplitude losses were less separated than in a larger (20° × 20°) test field.  相似文献   
103.
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104.
Transoral laser surgery for early glottic carcinoma   总被引:2,自引:0,他引:2  
This prospective study evaluates the oncological results of transoral laser surgery (TLS) for glottic carcinoma categorized Tis, T1 and T2 in a large, unselected group of 285 consecutive patients from a university-based referral center that uses transoral laser surgery as the standard approach to these tumors. Patients were treated between 1 January 1987 and 31 December 1996. Thirty-three patients had Tis disease, 174 T1 tumors and 113 T2. Main outcome measures were local control with initial therapy, ultimate local control, regional control, organ preservation, overall survival and cause-specific survival. The 5-year uncorrected actuarial survival for all 285 patients was 71.1%, and cause-specific actuarial survival was 98.7%. Local control with initial treatment was 85.9%, ultimate local control with salvage for local treatment failures 98.5%, and regional control 98.4%. In all, 94.3% had their larynges preserved after 5 years. Although favorable oncological results for early laryngeal carcinoma treated with laser surgery are supported this study, no definitive recommendations can be given for the best single treatment. Partial laryngectomies lead to the highest local control rates reported so far, radiotherapy is believed to preserve voice best and laser surgery is associated with time- and cost-effectiveness, low morbidity, fair local control rates and excellent re-treatment options in case of local failure. All specialists dealing with the treatment of early glottic carcinoma should be able to offer these different treatment modalities to their patients and to deal specifically with each patient’s individual needs and preferences. Received: 29 October 1998 / Accepted: 2 July 1999  相似文献   
105.
Purpose. Empirical formulae relate the mean size of primary droplets from jet and ultrasonic nebulizers to a fluid's physicochemical properties. Although the size selective filtering effects of baffling and evaporation may modify the secondary aerosol produced, this research sought to evaluate whether viscosity and surface tension of nebulized fluids influenced the aerosol's size and output characteristics. Methods. Fluid systems of different surface tension and viscosity (glycerol and propylene glycol solutions [10–50% (v/v)] and a range of silicone fluids [200/0.65 cs– l00cs]) were nebulized in three jet and two ultrasonic nebulizers. Secondary aerosol characteristics were measured with a Malvern 2600C laser diffraction sizer and the nebulization times, residual volumes and percentage outputs were determined. Results. While the droplet size appeared to be inversely proportional to viscosity for jet nebulizers, it was directly proportional to viscosity for ultrasonic nebulizers. Although fluid systems with lower surface tensions generally produced slightly smaller MMDs, the relationship between surface tension and droplet size was complex. The more viscous fluids required longer nebulization times and were associated with increased residual amounts (lower outputs). The ultrasonic nebulizers did not effectively, and were on occasion unable to, nebulize the more viscous fluids. Conclusions. It follows that there are cut-off values for viscosity and/or surface tension above or below which ultrasonic devices fail to operate. Moreover, jet nebulizers generated an aerosol with an optimum respirable output from median-viscosity fluids.  相似文献   
106.
成组序贯试验的原理和方法   总被引:4,自引:1,他引:3  
本文介绍了成组序贯试验的原理和方法。它可用于得到结果较慢(如数周或数月)及在整个试验过程中可分少数几个时间段来重复统计分析试验结果的情况。它既保留了传统序贯方法的优点又避免其局限性。当两种处理间确实存在差异时,它常可较早地得出结论,从而可减少样本量,缩短试验周期。特别在临床试验中它可尽早地使受试者停止接受较差的处理,符合伦理学的要求,同时又正好与临床试验中的期中分析相配合,可望有较大的发展前途。  相似文献   
107.
The gravity model, a method for analyzing transportation distribution in transportation engineering, was used to explain patient trips between ten health service regions in a Japanese prefecture. The OD (Origin-Destination) tables were constructed with zoning by regions, distinguishing between out- and inpatients. The observed trips were determined from the data of a survey conducted in 1992 that reported the locations of patient residences and chosen medical facilities. The base values used in the model calculations were the population size of each region and the road distance between the centers of regions. Problems of intrazonal trip were avoided by setting a mean intrazonal movement distance. This model was calibrated by the linear regression method with simultaneous validation by the index of correlation coefficients. The model was found to accurately simulate the effect of distance on the choice of medical facilities and the differences between the characteristics of in- and out-patients. The population value in use showed the relation not only with demand but also the supply of clinical services. It was suggested that the model presented here was useful in the allocation of medical resources and would help explain the relationship between suppliers and consumers of medical services.  相似文献   
108.
In this study a staff planning model for a health service clinic has been developed and validated using an example case of a health service clinic. The primary purpose of this research is to develop a representative staff planning model which balances the cost and benefits of staff task flexibility through crosstraining for a healthcare facility. Additionally, legal requirements for task substitution in the healthcare industry have been considered in the model.  相似文献   
109.
研究分散第二相Al2O3的含量及颗粒大小对PEO-NaSCN络合物电导的影响,结果表明:当颗粒度为0.7μm时,电导率比纯PEO-NaSCN提高了一个半数量级。颗粒度较大时,电导率均比纯PEO-NaSCN低,并在wAl2O3=0.25时,存在电导率最大的峰值。  相似文献   
110.
银杏叶注射液对实验性大鼠局灶性脑缺血的保护作用   总被引:5,自引:0,他引:5  
以行为障碍、脑梗死范围、脑含水量、脑组织病理改变为观察指标,研究银杏叶注射液(GBE)对大鼠大脑中动脉闭塞所致局部脑缺血的防治作用。结果表明,GBE20、40mg/kg静脉注射可显著降低大鼠脑梗死范围和脑含水量,改善行为障碍。脑组织形态学检查显示,GBE40mg/kg组动物脑组织缺血病变较轻。提示GBE对局灶性脑缺血具有保护作用。  相似文献   
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