一种新的选择性堵水措施：水敏性亚稳定体系的应用

该项目的目的是要开发一种新的化学体系，该体系一接触水就可形成一种堵塞相。目前开发的最新的化学体系分别是均质的水敏性溶液和水包油乳状液。这两种体系被水稀释后形成稳定的宏观乳液。在高含水的油藏中亚稳定体系转变成稳定的体系，在转变过程中水的粘度升高和通过孔洞的分散粒子被束缚从而限制水的流动。将有机硅、表面活性剂和天然原油作为一种分散剂进行测试。化学体系的流动特性可在天然砂岩体系中进行研究，相结构、相变以及粒径可通过光谱法和流变学方法进行分析。 岩心实验表明，在饱和的砂岩岩层中所有的亚稳定体系都可以将水的流量减小80％-90％。假设用硅树脂作为后置液，水的流动阻力将十分大，但同时地层污染也不可忽视。亚稳定体系是一种有效的单步渗透率调整液。 在成熟的气田和储藏设施中亚稳定体系是一种有效的堵水方式。该技术的独特之处是其只在水饱和油藏产生流动阻力；只在该技术失败时产生流动阻力。通过注油或注气可以消除流动隔层。     

Retrograde intramedullary nailing of femoral diaphyseal fractures

OBJECTIVES: To prospectively evaluate the results of retrograde intramedullary nailing of femoral shaft fractures. DESIGN: Prospective, consecutive series. PATIENTS AND SETTING: All patients with a femoral shaft fracture admitted at an urban Level 1 trauma center from December 1995 to December 1996 were treated with a retrograde femoral intramedullary nail. INTERVENTION: Retrograde femoral intramedullary nailing was performed on a radiolucent operating room table. Through a three-centimeter medial parapatellar incision, a reamed ten-millimeter retrograde nail was inserted. METHODS: From the time of injury until union, the following parameters were assessed: operative time, blood loss, extent of comminution, open grade, associated injuries, Injury Severity Score, body mass index, time to union, secondary procedures, range of motion in the knee. and complications. RESULTS: Fifty-seven patients with sixty-one fractures were available for follow-up, which averaged 43.1 weeks. Fifty-two percent of fractures demonstrated Winquist Type 3 or 4 comminution. Twenty-six percent of the fractures were open. Fifty-two fractures healed after the initial nailing, five of seven dynamized nails healed, and one patient with bone loss requiring bone graft united yielding a final union rate of 95 percent. Of the three nonunions (5 percent), two healed with exchange nailing and one remains asymptomatic at seventy-one weeks. One patient developed a late septic knee that resolved with treatment. Excellent range of motion in the knee was obtained by those patients who did not have other ipsilateral limb injuries. CONCLUSIONS: This consecutive series had a 95 percent union rate after nailing and dynamization as necessary. No knee problems were associated with the retrograde femoral intramedullary nailing technique. The one septic knee raises concerns about the use of retrograde nailing in severe open femoral shaft fractures. Retrograde femoral nailing should be given serious consideration as an alternative to antegrade femoral nailing.     

Constraints common to apparent motion in visual, tactile, and auditory space.

A point-like stimulus was presented in a clockwise or counterclockwise sequence at 3, 4, 6, or 12 uniformly spaced locations around a circle in visual, tactile, or auditory space. In 4 experiments, the simulators were (a) light-emitting diodes in the frontal plane, (b) mechanical stimulators on the palm, (c) airpuff nozzles around the head, and (d) loudspeakers around the head. For each spatial separation and stimulus-onset asynchrony (SOA) between successive stimuli around the circle, participants reported the direction of motion. Within each modality, the SOA required for 75% accurate discrimination of direction increased with the spatial separations. A time–distance constraint akin to Korte's third law of visual apparent motion can thus be obtained from responses that are objectively classifiable as correct or incorrect (without relying on subjective reports of "goodness" of apparent motion). Moreover, this time-distance constraint evidently generalizes across sensory modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigations of diffusion kinetics in Si/Ta/Cu/W and Si/Co/Ta systems by secondary neutral mass spectrometry

Proper understanding of the degradation mechanisms and diffusion kinetics of copper and cobalt interconnections for advanced microelectronics is important from the point of view of fundamental research and technology as well. In this paper Si(substrate)/Ta(10 nm)/Cu(25 nm)/W(10 nm) and Si(substrate)/Co(150 nm)/Ta(10 nm) samples, prepared by DC magnetron sputtering, were in investigated. The samples were annealed at several temperatures ranging from 423 K to 823 K for various times. The composition distributions were detected by means of Secondary Neutral Mass Spectrometry (SNMS). Microstructural characterization of samples was carried out by means of Transmission Electron Microscopy (TEM). It is shown that the changes in the composition profiles were mainly caused by grain boundary, GB, diffusion and the effective GB diffusion coefficients of Ta in Cu were determined both by the “first appearance” and “centre-gradient” methods. The activation energy is 100 kJ/mol. The importance of the Ta penetration into the Cu and its accumulation at the Cu/W interface can lead to an increase of the Ta content in the copper film. This can be an important factor in the change/degradation of the physical parameters (e.g. the electrical resistance) of interconnects. Furthermore a Ta segregation factor in Cu was evaluated. Preliminary results in the Si(substrate)/Co(150 nm)/Ta(10 nm) indicate fast (GB) diffusion of the Si into the Co layer, formation of a cobalt silicide layer at the Co/Si interface and Si accumulation first at the Ta/Co interface and later a retarded accumulation at the free Ta surface.     

Drosophila Rab39 Attenuates Lysosomal Degradation

Lysosomal degradation, the common destination of autophagy and endocytosis, is one of the most important elements of eukaryotic metabolism. The small GTPases Rab39A and B are potential new effectors of this pathway, as their malfunction is implicated in severe human diseases like cancer and neurodegeneration. In this study, the lysosomal regulatory role of the single Drosophila Rab39 ortholog was characterized, providing valuable insight into the potential cell biological mechanisms mediated by these proteins. Using a de novo CRISPR-generated rab39 mutant, we found no failure in the early steps of endocytosis and autophagy. On the contrary, we found that Rab39 mutant nephrocytes internalize and degrade endocytic cargo at a higher rate compared to control cells. In addition, Rab39 mutant fat body cells contain small yet functional autolysosomes without lysosomal fusion defect. Our data identify Drosophila Rab39 as a negative regulator of lysosomal clearance during both endocytosis and autophagy.     

Optimization of express line performance: numerical examination and management considerations

Improving the waiting process at checkouts in stores is an important goal of operations management in the era of time-based competition. The paper presents a method for evaluating the effect of express lines on the waiting process. An optimization model is developed which minimizes the average waiting time in line with respect to the maximum number of items allowed in the express lines. The research is based on a real case of a do-it-yourself superstore, but the methodology applied at the store can be used generally. The optimization model includes sensitivity analyses. Sensitivity analyses show how the optimal value of the limit parameter changes if major parameters of the model change. The results of these analyses help managers make decisions about short and medium-term operations of express lines.