Optimal control of non‐linear chemical reactors via an initial‐value Hamiltonian problem

The problem of designing strategies for optimal feedback control of non‐linear processes, specially for regulation and set‐point changing, is attacked in this paper. A novel procedure based on the Hamiltonian equations associated to a bilinear approximation of the dynamics and a quadratic cost is presented. The usual boundary‐value situation for the coupled state–costate system is transformed into an initial‐value problem through the solution of a generalized algebraic Riccati equation. This allows to integrate the Hamiltonian equations on‐line, and to construct the feedback law by using the costate solution trajectory. Results are shown applied to a classical non‐linear chemical reactor model, and compared against suboptimal bilinear‐quadratic strategies based on power series expansions. Since state variables calculated from Hamiltonian equations may differ from the values of physical states, the proposed control strategy is suboptimal with respect to the original plant. Copyright © 2005 John Wiley & Sons, Ltd.     

齐拉西酮注射液治疗躁狂发作激越症状的研究

目的：以氟哌啶醇注射液为对照,评价齐拉西酮注射液治疗躁狂发作急性期激越患者的疗效及安全性。方法：符合ICD-10双相I型躁狂发作诊断标准的患者70例,随机分配到齐拉西酮注射液治疗组（试验组）和氟哌啶醇注射液治疗组（对照组）各35例,对患者进行基线评价,以及肌注治疗后的2、12、24、48和72h的评价。采用PANSS兴奋因子量表评价主要疗效,采用副反应症状量表（TESS量表）评定药物的不良反应。结果：两组72h时试验组总有效率为71．43％,对照组总有效率为68．57％。药物治疗72h后与基线比较,试验组PANSS兴奋因子得分减分平均为（11．32±4．15）分,对照组PANSS兴奋因子得分减分平均为（11．76±4．23）分。两组主要疗效指标差异无统计学意义（P〉0．05）。试验组锥体外系不良反应较对照组明显减少,TESS量表评分在治疗前后差异无统计学意义（P〉0．05）;对照组出现锥体外系不良反应较多,治疗前后差异有统计学意义（P〈0．05）。结论：甲磺酸齐拉西酮注射液可快速有效控制躁狂发作的激越症状,疗效与氟哌啶醇注射液相当,但安全性更高。     

Survey of physician practices for community-dwelling agitated dementia patients

In order to gain a better understanding of physician clinical reasoning and clinical practices for community-dwelling agitated dementia patients, we conducted a small survey of geriatric psychiatrists, primary care physicians and neurologists. The survey asked physician respondents to give a likelihood estimate of how often they would carry out one of 13 different pharmacologic and psychosocial interventions. Intervention by specialty group analyses found that geriatric psychiatrists were more likely to recommend neuroleptic medications and dementia support group activities, but less likely to recommend referral to behavioral specialists than the other physician groups. Neurologists were more likely to recommend dementia support groups than primary care physicians, but they were also more likely to recommend institutional placement than the other physician groups. Primary care physicians were more likely to recommend hydroxyzine than either neurologists or geriatric psychiatrists. Multivariate ordinal logistic regression analysis found that older physicians and primary care physicians expressed a lower likelihood of recommending dementia day care programs and a higher likelihood of recommending hydroxyzine. Women physicians, however, expressed a high likelihood of recommending dementia day care programs. The results of the survey suggest that personal and specialty characteristics of physicians influence the types of treatment recommendations made for agitated dementia patients. The results may help community-based dementia care programs to develop strategies that broaden physician involvement in multidisciplinary team management for these patients.     

Tardive akathisia and agitated depression during metoclopramide therapy

The authors describe two cases of tardive akathisia following metoclopramide therapy, in which there were concomitant symptoms of agitated depression.     

随机返混对颗粒反应的影响

针对多级返混流系统,比较了Markov过程模型与Monte Carlo方法的区别。采用Monte Carlo方法模拟了返混的波动对反应率的影响,给出了几种常见反应过程中返混对颗粒反应率影响的模拟结果。     

自吸式搅拌鼓泡反应器测定气液平衡数据

本法集取了流动法和循环法的优点、具有测定速度快、设备结构紧凑、测控装置简单、操作方便等特点。在温度30～70℃、二氧化碳分压0.01～0.113 3MPa、N-甲基二乙醇胺(MDEA)浓度20～50%(wt)的条件下,测定了MDEA-CO_2-H_2O系统的相平衡数据。平衡时间仅为文献值的1/4～1/2。     

小颗粒滴流床反应器中压降和持液量关联式

通过对滴流床中气液并流向下流动形式进行理论分析,推导出压降和持液量的关系,提出了计算滴流床反应器中持液量的新方法。实验和文献数据证明,在高相互作用区,此方法计算结果比较满意。同时,也得到高相互作用区下的压降关联式。     

Joint state and parameter estimation for a nuclear reactor with fast and slow modes

The knowledge of the process state variables and coefficients is of substantial importance in many practical domains such as process control and fault detection and diagnosis. In practice, one encounters systems composed of both static and dynamic models owing to the natural difference in time response of various process variables. This paper presents an estimation algorithm for a system described by the coupled steady state and dynamic models via formulating the joint state and parameter estimation problem as a state estimation problem and using a filter for non-linear systems. In the algorithm the error covariance matrix prior to the current measurements is updated using the filtered estimates rather than the predicted quantities, having a basal impact on the convergence behaviour. The other important aspect considered is the inclusion of the unmeasured disturbances in the parameter vector. This concept has an important implication for improving the on-line detection and diagnosis of potential plant operational problems. A sodium-cooled nuclear reactor is the application problem illustrating the effectiveness of the proposed scheme.     

Excited Delirium Syndrome (ExDS): Defining Based on a Review of the Literature

Background

Patients present to police, Emergency Medical Services, and the emergency department with aggressive behavior, altered sensorium, and a host of other signs that may include hyperthermia, “superhuman” strength, diaphoresis, and lack of willingness to yield to overwhelming force. A certain percentage of these individuals will go on to expire from a sudden cardiac arrest and death, despite optimal therapy. Traditionally, the forensic community would often classify these as “Excited Delirium” deaths.

Objectives

This article will review selected examples of the literature on this topic to determine if it is definable as a discrete medical entity, has a recognizable history, epidemiology, clinical presentation, pathophysiology, and treatment recommendations.

Discussion

Excited delirium syndrome is characterized by delirium, agitation, acidosis, and hyperadrenergic autonomic dysfunction, typically in the setting of acute-on-chronic drug abuse or serious mental illness or a combination of both.

Conclusions

Based upon available evidence, it is the consensus of an American College of Emergency Physicians Task Force that Excited Delirium Syndrome is a real syndrome with uncertain, likely multiple, etiologies.