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41.
R Kneen NG Pham T Solomon TM Tran TT Nguyen BL Tran J Wain NP Day TH Tran CM Parry NJ White 《Canadian Metallurgical Quarterly》1998,27(4):845-850
PURPOSE: To review the University of Florida experience in treating ependymomas, analyze prognostic factors, and provide treatment recommendations. METHODS AND MATERIALS: Forty-one patients with ependymoma and no metastases outside the central nervous system received postoperative radiotherapy with curative intent between 1966 and 1989. Ten patients had supratentorial lesions, 22 had infratentorial lesions, and 9 had spinal cord lesions. All patients had surgery (stereotactic biopsy, subtotal resection, or gross total resection). Most patients with high-grade lesions received radiotherapy to the craniospinal axis. Low-grade intracranial lesions received more limited treatment. Spinal cord lesions were treated using either partial spine or whole spine fields. RESULTS: Of 32 intracranial tumors, 21 recurred, all at the primary site; no spinal cord tumors recurred. Overall 10-year survival rates were 51% (absolute) and 46% (relapse-free); by tumor site: spinal cord, 100%; infratentorial, 45%; supratentorial, 20% (p = 0.002). On multivariate analysis, tumor site was the only factor that influenced absolute survival (p = 0.0004); other factors evaluated included grade, gender, age, duration of symptoms, resection extent, primary tumor dose, treatment field extent, surgery-to-radiotherapy interval, and days under radiotherapy treatment. CONCLUSIONS: Patients with supratentorial or infratentorial tumors receive irradiation, regardless of grade. Craniospinal-axis fields are used when spinal seeding is radiographically or pathologically evident. Spinal cord tumors are treated using localized fields to the primary site if not completely resected. Failure to control disease at the primary site remains the main impediment to cure. 相似文献
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The Toyota Production System (TPS) can result in huge benefits for companies and has been widely implemented around the world. Nevertheless, most adopters emphasize only the technical practices of the TPS, but neglect the critical role of human factors in the implementation of the TPS. Therefore, this study aims at developing an integrated TPS model that fully integrates the technical elements and human elements of the TPS with Total Quality Management (TQM) practices. An empirical study was conducted to confirm the causal relationships among these constructs. In the empirical study, questionnaires were mailed and e‐mailed to 620 companies that had implemented the TPS, and 151 of the completed questionnaires were valid. These 151 respondents were divided into eight categories. The results revealed that the implementation level of each construct was significantly different in each industry. The automobile and motorcycle industries have put a great deal of effort into the application of Humanity, Human Resource Management (HRM), and TQM practices and obtained good results. Other industries, however, ignored the implementation of HRM practices. The results also revealed that the early adopters enjoyed significant benefits from the implementation of the TPS, which led high‐tech companies to start adopting TPS practices and become lean enterprises. © 2011 Wiley Periodicals, Inc. 相似文献
45.
Palm-oil-in-water emulsions were prepared with mixtures of Tween 40 and Span 40 in various proportions. Stability and droplet-size
distribution of the emulsions were monitored. Interfacial tensions of the palm oil/water interface were also determined in
the presence of these emulsifier mixtures. Emulsifying efficiency of the emulsifier mixtures was assessed. No synergistic
effect of Tween 40 (sorbitan monopalmitate with 18–22 moles of ethylene oxide) and Span 40 (sorbitan monopalmitate) was found
on interfacial tension. Tween 40 alone (hydrophilic-lipophilic balance value 15.6) at 1.0% w/w gave palm oil emulsions that
were stable for more than 30 d at 60°C. Emulsifier mixtures of Tween 40 and Span 40 with hydrophilic-lipophilic balance values
in the range of 8.0–8.6 produced stable emulsions only at much higher emulsifier-mixture concentrations. The inherent nature
of the oil and the accompanying natural surface-active materials present in the oil can influence the prevailing conditions
at the oil/water interface and alter composition of the interfacial film and hence its stability. 相似文献
46.
Fluor公司开发的Fluor SOx净化工艺具有广泛多样的工艺布局,可以通过经济的方式定制脱除烟气中的有害组成。该工艺几乎能去除全部SOx并减少CO排放。Fluor SOx净化工艺的主要步骤已在多套工业装置中得到成功的证实。除技术可行、经济合理之外,Fluor SOx净化工艺不会产生任何有害副产物,也不会遇到与SOx有关的腐蚀问题。此外,该工艺生产高纯度可市售的元素硫。论述了Fluor SOx净化工艺的特征、技术和成本优势、设计和操作的简易性以及实施的便利性。 相似文献
47.
Fluor公司开发的Fluor SO_2净化工艺具有广泛多样的工艺布局,可以通过经济的方式定制脱除烟气中的有害组成。该工艺几乎能去除全部SO_2并减少CO排放。Fluor SO_x净化工艺的主要步骤已在多套工业装置中得到成功的证实。除技术可行、经济合理之外,Fluor SO_x净化工艺不会产生任何有害副产物,也不会遇到与SO_3 有关的腐蚀问题。此外,该工艺生产高纯度可市售的元素硫。论述了Fluor SO_x净化工艺的特征、技术和成本优势、设计和操作的简易性以及实施的便利性。 相似文献
48.
The business value of information technology (IT) has been one of the top concerns of both practitioners and scholars for decades. Numerous studies have documented the positive effects of IT capability on organizational performance but our knowledge of the processes through which such gains are achieved remains limited due to a lack of focus on the business environment. Such a linkage therefore remains the subject of debate in the information systems literature. In this study, we fill this gap by investigating the mediating role of business process agility and the moderating roles of environmental factors. On the basis of matched survey data obtained from 214 IT and business executives from manufacturing firms in China, our analyses show that even though firm-wide IT capability presents the characteristics of rarity, appropriability, non-reproducibility, and non-substitutability, its impact on organizational performance is fully mediated by business process agility. Our results also show that the impact of the environment is multifaceted and nuanced. In particular, environmental hostility weakens the effect of IT capability on business process agility, while environmental complexity strengthens it. The theoretical and practical implications of this study, and its limitations, are also discussed. 相似文献
49.
Initial cholesterol uptake by everted sacs of rat small intestine: Kinetic and thermodynamic aspects
The kinetics of initial cholesterol uptake by everted rat proximal and distal small intestinal sacs were evaluated in vitro.
The mucosal incubation solution consisted of 0.05 mM cholesterol solubilized in 4.8 mM sodium taurocholate micellar solution
at pH 7.4. Experiments were performed at temperatures from 26 to 38 C. The rate of cholesterol uptake followed a linear relationship
when plotted against time indicating an apparent zero-order kinetics mechanism for initial uptake. An Arrhenius plot of the
results of uptake versus temperature remained linear over the entire range of temperatures studied. The large free energy
of activation (20 kcal/mole) suggests that an energy barrier for cholesterol uptake exists at the enterocyte luminal cell
membrane and may be an important limiting step in cholesterol uptake. It is proposed that a transient association between
cholesterol and a component of the enterocyte luminal cell membrane is formed during initial uptake of cholesterol. The transient
association may be an activated complex formed with proteins present at or within the luminal enterocyte cell membrane. 相似文献
50.
Biing-Hwa Yan Hsinn-Jyh Tzeng Fuang Yuan Huang Yan-Cherng Lin Han-Ming Chow 《International Journal of Machine Tools and Manufacture》2007,47(6):920-926
This study presents a spiral polishing method and a device for micro-finishing purposes. This novel finishing process has wider application than traditional processes. This offers both automation and flexibility in final machining operations for deburring, polishing, and removing recast layers, thereby producing compressive residual stresses even in difficult to reach areas. Applying of this method can obtain a fine polished surface by removing tiny fragments via a micro lapping generated by transmission of an abrasive medium through a screw rod. The effect of the removal of the tiny fragments can be achieved due to the function of micro lapping. The method is not dependent on the size of the work-piece's application area in order to carry out the ultra precise process. The application of this research can be extended to various products of precision ball-bearing lead screw. The proposed method produces products with greater precision and more efficiently than traditional processes, in terms of processing precisions and the surface quality of products. These parameters used in achieving maximum material removal rate (MRR) and the lowest surface roughness (SR) are abrasive particle size, abrasive concentration, gap, revolution speed and machining time. 相似文献