Advanced off-column technologies for capillary electrophoresis : microfluidic deposition, two-dimensional separations, and surface-enhanced Raman scattering-based detection

Capillary electrophoresis (CE) Is a widely accepted technique for performing high-efficiency liquid separations. The utility of CE separations could be increased by comprehensively depositing the capillary effluent onto a planar substrate, thus essentially preserving the separation to allow the application of off-column technologies. Electrospray is a convenient technique for continuously transferring column effluent from capillary-toplanar format. Conditions are optimized to produce a narrow (~ 20 pm) liquid filament (electrofilament), which is capable of depositing spatially focused bands with track widths that are routinely 100-200 pm. A fiber optic-based laser-induced fluorescence cell is employed to monitor the separation on-column while the separated bands are deposited onto a moving substrate. The electrofilament (EF) technique is evaluated based on its ability to deposit spatially focused bands, which preserve the on-column separation performance. The EF technique was used to couple CE with thin-layer chromatography (TLC) to demonstrate a convenient technique for performing two-dimensional microseparatlons. The TLC plate stores the separation from the CE capillary in the first dimension and then serves as the stationary phase for the separation in the second dimension. To demonstrate this technique, dansylated derivatives of select amino acids are separated in the first dimension by micellar electrokinetic chromatography, and in the second dimension their enantiomers are separated by reversed-phase TLC using a mobile phase that contains cyclodextrins as a chiral reagent. Prior to TLC development, off-column CE efficiencies of 130,000 to 190,000 plates per meter were obtained. The enantiomers of four DNS-amino acids are baseline resolved and a significant improvement in peak capacity over the one dimensional separation is demonstrated. Surface-enhanced Raman scattering (SERB) is employed to obtain distinctive spectra for compounds that are separated by CE and EF deposited onto planar SERS-active substrates. A simple method is described that explains how to prepare SERS-active substrates by depositing a silver-colloid solution onto frosted-glass microscope slides. Scanning electron micrographs reveal a layered coating of fairly uniform-sized, 100-nm silver nanoparticles with interstitial spaces ranging from a few to tens of nanometers. The test compounds used to demonstrate this technique include compounds of biological significance: benzyloxyresorufin, riboflavin, and resorufin. Characteristic spectra with major Raman bands exhibiting signal-to- noise of greater than 3 were obtained for a 3.2-nL injection of 10 ® M (706 fg) resorufin. Forming a self-assembled monolayer on the substrate increases the sensitivity of the SERS technique and decreases the on-substrate broadening of deposited bands

Small Payload Accommodations (SPA) for the ATLAS Family of Launch Vehicles

The history of small, secondary payload accommodations on early ATLAS boosters is reviewed. Design and flight operations concepts for small payloads on current ATLAS launch vehicles are presented and discussed. ATLAS launch vehicle system capabilities are presented in terms of launch site integration schedules and the excess performance which will be available to launch small payloads

APPRAISING THE EFFECTS OF THE AGRICULTURAL ACT OF 1970 UPON OKLAHOMA'S ECONOMY

Agricultural and Food Policy,

An Evaluation of Columbia Villa/Tamaracks Community Service Intervention Project

The Community Service Intervention Program (CSlP) is a unique public agency response to a multifaceted set of problems confronting low income residents living in Oregon \u27s largest public housing project. The primary goals of the CSIP are to reduce crime, reduce the fear of crime among residents, and to improve the quality of life of the families living in Columbia Villa/Tamaracks. The evaluation of the CSIP combined a number of different research methods, on different analytical levels, to provide a summary assessment. Data were collected from individuals, from agencies, and from police records in a post facto analysis of the CSIP. Recommendations include: a higher profile by the County to coordinate, plan, manage, and evaluate services according to a set of carefully chosen set of objectives; a longitudinal evaluation of CSIP efforts; greater involvement by Columbia Villa/Tamaracks residents; greater job opportunities and job training for Columbia Villa/Tamaracks residents; additional participation in the CSIP by the Fire Department, Tri-Met, Metro (Solid Waste), and DEQ

Chiasma

Newspaper reporting on events at the Boston University School of Medicine in the 1960s

Cutaneous Blood Flow and Percutaneous Absorption: A Quantitative Analysis Using a Laser Doppler Velocimeter and a Blood Flow Meter

Cutaneous blood flow has been directly quantitated in vivo for the first time without animal death utilizing the rat skin sandwich flap. This was accomplished by conducting experiments that made a direct correlation between two instruments: a laser Doppler velocimeter and an electromagnetic blood flow meter. Data demonstrate that the correlation between these two instruments is high and reproducible (r = 0.96) with a small (1.3%) coefficient of variation. Blood flow to skin in the unmanipulated state varies from 0.7 to 1.2 mls/min in an anesthetized rat. Application of the blood flow correlation to the determination of percutaneous absorption of caffeine across human skin and benzoic acid across rat skin demonstrates that assuming cutaneous blood flow is a particular value day to day in any skin type results in an apparent wide range of total compound absorbed across that skin on independent occasions. Utilizing actual blood flow measurements to calculate the amount of chemical absorbed reduces the range of variability in the total amount of chemical absorbed and provides a more accurate knowledge of events occurring during a particular time of the absorption process. Quantitation of cutaneous blood flow will be useful in physiologic and pharmacologic studies where actual cutaneous blood flow is likely to be important to the processes studied, e.g., delivery of drug to skin, metabolism within the skin, and disposition of drug to blood and skin following topical drug application

Dynamic System Representation of Basic and Non-Linear in Parameters Oscillatory Motion Gestures

We present a system for generation and recognition of oscillatory gestures. Inspired by gestures used in two representative human-to-human control areas, we consider a set of oscillatory (circular) motions and refine from them a 24 gestures lexicon. Each gesture is modeled as a dynamic system with added geometric constraints to allow for real time gesture recognition using a small amount of processing time and memory. The gestures are used to control a pan-tilt camera neck. The gesture lexicon is then enhanced to include non-linear in parameter ( come here ) gesture representations. An enhancement is suggested which would enable the system to be trained to recognized previously unidentified yet consistent human generated oscillatory motion gestures

Multimodal Imaging of Photoreceptor Structure in Choroideremia

Purpose Choroideremia is a progressive X-linked recessive dystrophy, characterized by degeneration of the retinal pigment epithelium (RPE), choroid, choriocapillaris, and photoreceptors. We examined photoreceptor structure in a series of subjects with choroideremia with particular attention to areas bordering atrophic lesions. Methods Twelve males with clinically-diagnosed choroideremia and confirmed hemizygous mutations in the CHM gene were examined. High-resolution images of the retina were obtained using spectral domain optical coherence tomography (SD-OCT) and both confocal and non-confocal split-detector adaptive optics scanning light ophthalmoscope (AOSLO) techniques. Results Eleven CHM gene mutations (3 novel) were identified; three subjects had the same mutation and one subject had two mutations. SD-OCT findings included interdigitation zone (IZ) attenuation or loss in 10/12 subjects, often in areas with intact ellipsoid zones; RPE thinning in all subjects; interlaminar bridges in the imaged areas of 10/12 subjects; and outer retinal tubulations (ORTs) in 10/12 subjects. Only split-detector AOSLO could reliably resolve cones near lesion borders, and such cones were abnormally heterogeneous in morphology, diameter and density. On split-detector imaging, the cone mosaic terminated sharply at lesion borders in 5/5 cases examined. Split-detector imaging detected remnant cone inner segments within ORTs, which were generally contiguous with a central patch of preserved retina. Conclusions Early IZ dropout and RPE thinning on SD-OCT are consistent with previously published results. Evidence of remnant cone inner segments within ORTs and the continuity of the ORTs with preserved retina suggests that these may represent an intermediate state of retinal degeneration prior to complete atrophy. Taken together, these results supports a model of choroideremia in which the RPE degenerates before photoreceptors