系统内可编程时钟提高设计灵活性和便携性

先进电子系统的功能与特性的整合在持续快速发展,这导致了目前时钟网络设计中的许多主要障碍。为满足各种芯片和接口在频率、I/O和性能方面对时钟的需求,经常需要既没有灵活性,也不具备便携性的非常精确的执行。最终的结果往往是一个由多个分散的振荡器和缓冲器组成的支离破碎的解决方案,只要系统要求不改变,它就可以工作。这种方法会使物料成本(BOM)、库存管理和设计资源的成本居高不下。进入新的多PLL时代,可编程时钟通过采用I2C和JTAG这样的行业标准接口,加上非易失性存储器就可以达到解决这些挑战的目标。通过通用接口实现系统内…     

Anandamide synthesis is induced by arachidonate mobilizing agonists in cells of the immune system

The hypothesis that the capability of agents to mobilize arachidonic acid (AA) could predict increased anandamide (ANA) synthesis in a macrophage cell line has been examined. Lipopolysaccharide (LPS), platelet-activating factor (PAF) and cannabinoids such as Delta9-tetrahydrocannabinol (THC) and anandamide were all found to be agonists for the release of AA and led to increased ANA synthesis in RAW264.7 mouse macrophage cells. Nitric oxide, in contrast, stimulated AA release without raising ANA levels. ANA stimulation of its own synthesis indicates the existence of a positive feedback mechanism. The possible involvement of the CB2 receptor in THC-mediated AA release and ANA synthesis is addressed using the antagonist SR144528. ANA synthesis is also increased by the combination of calcium ionophore and indomethacin, suggesting that ANA is metabolized by a cyclooxygenase in this system. The data imply that ANA could play a role in the response of the immune system to cannabinoids and bacterial endotoxins and that AA mobilization is a predictor for increased ANA synthesis.     

Isolated sphenoethmoid recess polyps

PURPOSE: The Marshall-Smith Syndrome (MSS) is a rare disease characterized by orofacial dysmorphism, failure to thrive, accelerated osseous maturation and mental retardation. It has anaesthetic implications due to upper airway problems and possible atlanto-axial instability. We present the perioperative problems (difficult intubation, airway obstruction) encountered in a child with MSS who underwent several anaesthetics during his first two years of life. CLINICAL FEATURES: At birth, the child presented with asphyxia due to obstructive apnoea. His trachea was, therefore, intubated immediately. The morphological diagnosis of MSS was confirmed by the pathognomonic radiological appearance of the bones (bone age was eight months at the age of four days). Upper airway difficulty was caused by functional problems at the level of the hypopharynx (inspiratory collapse at the level of the velum palatinum), and was solved by the use of a nasopharyngeal airway (NPA) during the induction of anaesthesia and early postoperative period. CONCLUSION: The use of an NPA during both induction and recovery of anaesthesia may be particularly useful to prevent upper airway problems in children with MSS.     

Use of cumulative meta-analysis in the design, monitoring, and final analysis of a clinical trial: a case study

From 1983 to 1987, the Department of Veterans Affairs (DVA) Cooperative Studies Program (CSP) conducted a multicenter clinical trial (CSP #207) to determine whether four different antiplatelet regimens compared to placebo could prevent the occlusion of grafts following coronary artery bypass surgery. The study showed that all of the active regimens tended to be better than placebo and that the three regimens containing aspirin were statistically significantly better. A cumulative meta-analysis of 12 trials performed shortly before the end of CSP #207 raised the issue as to whether the meta-analysis, if done earlier, would have changed the conduct of the trial. At the start of the planning period, one trail of size n = 37 had been published with a nonsignificant odds ratio (OR) of 0.74 (95% CI: 0.18, 3.12). At the time that CSP # 207 was approved by the DVA Cooperative Studies Evaluation Committee, two trials had been published (cumulative n = 150, OR = 0.44, 95% CI 0.19, 0.99). At the time patient intake started, five trials showed cumulative n = 769, OR = 0.42, 95% CI = 0.26, 0.68. Although the first 6-month CSP #207 progress report showed no treatment effect, by the time of the 12-month review by the Data Monitoring Board (DMB) a trend was developing in favor of active treatment. If the results of the meta-analysis had been available to the DMB at that time, conceivably the Board would have recommended stopping the placebo arm because of a convincing treatment effect based on the totality of the evidence. Cumulative meta-analysis could be useful as an adjunct in the planning, conduct, and final analysis of a clinical trial. It could also be used as one piece of evidence in the monitoring of the ongoing phase of a trial.     

Reconstructive and plastic microsurgery in the treatment of combat trauma to the extremities

In the department of microsurgery of A.A. Vishnevsky Central Hospital the transplantation and transposition of the at the gunshot injuries of the extremities have begun to execute since 1990. For this time 94 surgical interventions have been conducted at 88 wounded: 57 transplantations and 37 transpositions of the bloody tissues. The transplantation and transposition of the vascularized complexes of tissues with application of microsurgical technique is the effective method of the treatment of the wounded in the extremities. In the conditions of the local armed conflicts it is necessary to provide deployment of the department of microsurgery at stages of the specialized medical care.     

Efficient decision tree design for discrete variable pattern recognition problems

An algorithm is developed for the design of an efficient decision tree with application to the pattern recognition problems involving discrete variables. The problem of evaluating an extremely large number of trees in search of a minimum cost decision tree is tackled by defining a criterion to estimate the minimum expected cost of a tree in terms of the weights of its terminal nodes and costs of the measurements, which then is used to establish the search procedure for the efficient decision tree. The concept of prime events is used to obtain the number of modes and the corresponding weights in the design samples. An application of the proposed algorithm is presented for the design of an efficient decision tree for classifying Devanagri numerals.