Reliability of seizure classification using a semistructured interview

Methods for standardized classification of epileptic seizures are important for both clinical practice and epidemiologic research. In this study, we developed a strategy for standardized classification using a semistructured telephone interview and operational diagnostic criteria. We interviewed 1,957 adults with epilepsy ascertained from voluntary organizations. To confirm and expand the seizure history, we also interviewed a first-degree relative for 67% of subjects and obtained medical records for 59%. Three lay reviewers used all available information to classify seizures. To assess reliability, each reviewer classified a sample of subjects assigned to the others. In addition, an expert physician classified a sample of subjects assigned to two of the reviewers. Agreement was "moderate-substantial" for generalized-onset seizures, both for the comparisons between pairs of lay reviewers and for the neurologist versus lay reviewers. Agreement was "substantial-almost perfect" for partial-onset seizures, both for pairs of lay reviewers and for the neurologist versus lay reviewers. These results suggest that seizures can be reliably classified by lay reviewers, using operational criteria applied to symptoms ascertained in a semistructured telephone interview.     

Liposome-cell interaction: transfer and intracellular release of a trapped fluorescent marker

When small, unilamellar lipid vesicles containing a high concentration of the fluorescent dye 6-carboxyfluorescein are incubated with either frog retinas or human lymphocytes, fluroescence distributes widely throughout each cell. Since "self-quenching" largely prevents the dye from fluorescing as long as it remains sequestered in vesicles, it is clear that a considerable amount of dye is released from the vesicles and diluted into the much larger volume of the cell.     

Fibrous myopathy. A rheumatic complication of drug abuse

A progressive fibrous myopathy may result from chronic intramuscular drug abuse. This complication may mimic other rheumatic disorders and early recognition may prevent disability. The patient described here presented with fixed flexion and extension contracture of hips and knees, respectively, after abusing meperidine and other agents for 3 years. Soft tissues of thighs and buttocks were "wood hard," EMG showed absence of action potentials in affected muscles, and biopsy revealed extensive replacement of muscle with dense, acellular fibrous tissue. Possible mechanisms are discussed.     

Comparative performance of open and totally enclosed machines

Continuous improvements in insulating materials, manufacturing consistencies in sealed windings and extensive laboratory testing of various systems show that synchronous machines with NEMA II construction can replace totally enclosed machines. Tests on windings in corrosive atmospheres show that sealed insulation systems are impervious to the environment. Standard maintenance ensures that incendive arcing will not be generated in potentially hazardous environments. When compared to totally enclosed machines, the NEMA II-type construction is lighter, more efficient, has lower short-circuit current and associated torques and is easier to maintain     

Labelled-replica techniques: post-shadow labelling of intramembrane particles in freeze-fracture replicas

Three methods are described for direct post-fracture, post-shadow labelling of individual classes of intramembrane particles (IMPs) in freeze-fracture replicas of biological membranes. The P-face IMPs corresponding to the acetylcholine receptor complexes (AChRs) of vertebrate neuroeffector junctions are identified by post-replication labelling with ferritin-antibody complexes and with neurotoxin-biotin-avidin-colloidal gold affinity ligands. (The freeze-etch nomenclature of Branton et al., 1975, is used in this report.) These post-shadow labelling techniques resemble conventional en bloc labelling techniques except that the labelling reagents must penetrate a thin but discontinuous layer of platinum superimposed on the molecules of interest. In the ‘sectioned labelled-replica technique’, the replicated and labelled tissues are stained, embedded in plastic and sectioned parallel to the replica-tissue interfaces. In the direct ‘labelled-replica techniques’, the replicated and labelled samples are freeze-dried or critical point dried, the labelled surfaces are stabilized by carbon coating, and the underlying tissues are dissolved, allowing the labelled-replicas to be examined as conventional freeze-fracture replicas. The unshadowed side of each AChR IMP is shown to retain sufficient biochemical information to permit both immunospecific and neurotoxin specific labelling despite formaldehyde fixation, freezing, fracturing, platinum shadowing, and thawing in aqueous media. A new mixed ferricyanide-osmium staining method reveals electron opaque structures spanning the membrane bilayer in the same size, number and distribution as the labelled IMPs. These experiments demonstrate the feasibility of identifying individual IMPs in freeze-fracture replicas and may allow the identification of specific membrane lesions in human disease.     

Establishing a limit of recognition for a vapor sensor array

Organic vapor analysis with microsensor arrays relies principally on two output parameters: the response pattern, which provides qualitative information, and the response sensitivity, which determines the limit of detection (LOD). The latter is used to define the operating limit in the low-concentration range, under the implicit assumption that, if a vapor can be detected, it can be identified and differentiated from other vapors on the basis of its response pattern. In this study, the performance of an array of four polymer-coated surface acoustic wave vapor sensors was explored using calibrated response data from 16 solvent vapors in Monte Carlo simulations coupled with pattern recognition analysis. The statistical modeling revealed that the ability to recognize a vapor from its response pattern decreases with decreasing vapor concentration, as expected, but also that the concentration at which errors in vapor recognition become excessive is well above the calculated LOD in most cases, despite the LOD being based on the least sensitive sensor in the array. These results suggest the adoption of a limit of recognition (LOR), defined as the concentration below which a vapor can no longer be reliably recognized from its response pattern, as an additional criterion for evaluating the performance of multisensor arrays. A generalized method for estimating the LOR is presented, as well as a means for improving the LOR via residual error analysis.     

梳齿的不平行对电容式微机械传感器阶跃信号响应的影响

分析了梳齿电容式传感器在三种电容驱动方式下,梳齿电容极板的不平行对传感器受到阶跃加速度信号作用时可靠工作条件的影响。得到了梳齿倾斜效应对传感器阶跃加速度响应影响的分析模型。结果表明梳齿电容在同样的电压驱动下,若电容极板的倾斜角变到0.5°时,对于单边电容结构、双边电容结构和有力反馈的双边电容结构,传感器能够承受的临界阶跃加速度分别变为电容极板完全平行时的0.34、0.44、0.52。并针对DRIE工艺刻蚀梳齿的原理,讨论了改进梳齿不平行的方法。     

Accelerated image reconstruction using ordered subsets of projection data

The authors define ordered subset processing for standard algorithms (such as expectation maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is defined as a single pass through all the subsets, in each subset using the current estimate to initialize application of EM with that data subset. This approach is similar in concept to block-Kaczmarz methods introduced by Eggermont et al. (1981) for iterative reconstruction. Simultaneous iterative reconstruction (SIRT) and multiplicative algebraic reconstruction (MART) techniques are well known special cases. Ordered subsets EM (OS-EM) provides a restoration imposing a natural positivity condition and with close links to the EM algorithm. OS-EM is applicable in both single photon (SPECT) and positron emission tomography (PET). In simulation studies in SPECT, the OS-EM algorithm provides an order-of-magnitude acceleration over EM, with restoration quality maintained.     

微胶囊技术在啤酒生产中的应用研究

介绍了微胶囊固定化啤酒酵母细胞的原理以及研究了影响微胶囊稳定性的几个关键因素,阐述了微胶囊技术在啤酒连续生产应用中的可行性,结果表明连续发酵生产的啤酒与分批发酵相比,风味、口感都比较接近.     

一种中频接收电路的版图设计

利用Cadence版图设计工具采用B300工艺对一种中频接收电路芯片的版图设计实例,阐述了模拟集成电路版图的设计过程,论述了包括单元库建立、布局、布线、设计规则检查（DRC）和版图对照原理图检查（LVS）等在内的设计步骤以及进行每一步骤的具体方法,尤其对布局和布线这样的关键步骤进行了重点讨论。最后给出了完整的芯片版图。