Publications by authors named "Sheaff C"

Regulatory guidelines for tissue engineered products require stringent characterization during production and necessitate the development of novel, non-destructive methods to quantify key functional parameters for clinical translation. Traditional assessments of engineered tissues are destructive, expensive, and time consuming. Here, we introduce a non-destructive, inexpensive, and rapid sampling and analysis system that can continuously monitor the mechanical, biochemical, and structural properties of a single sample over extended periods of time.

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There is a critical need to develop noninvasive, nondestructive methods for assessing the quality of engineered constructs prior to implantation. Currently, the composition and maturity of engineered tissues are assessed using destructive, costly, and time-consuming biochemical and mechanical analyses. The goal of this study was to use noninvasive, multimodal imaging to monitor osteogenic differentiation and matrix deposition by human mesenchymal stem/stromal cells (MSCs) during in vitro culture.

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This paper presents the first attempt at combining Cloud with Graphic Processing Units (GPUs) in a complementary manner within the framework of a real-time high performance computation architecture for the application of detecting and tracking multiple moving targets based on Wide Area Motion Imagery (WAMI). More specifically, the GPU and Cloud Moving Target Tracking (GC-MTT) system applied a front-end web based server to perform the interaction with Hadoop and highly parallelized computation functions based on the Compute Unified Device Architecture (CUDA©). The introduced multiple moving target detection and tracking method can be extended to other applications such as pedestrian tracking, group tracking, and Patterns of Life (PoL) analysis.

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Background: Many individuals with moderate and severe stroke are unable to use their paretic hand. Currently, the effect of conventional therapy on regaining meaningful hand function in this population is limited. Efforts have been made to use brain-machine interfaces (BMIs) to control hand function.

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All-optical transduction of ultrasound provides high-frequency (>20 MHz) operation in the absence of electrical noise and distortion that hinders small-scale piezoelectric probes. Although fabrication of an all-optical 2-D array suitable for in vivo imaging remains incomplete, a thin-film structure integrating a polyimide film with a Fabry-Perot (etalon) receiver has been shown to be a viable candidate. We present here incremental improvements in the performance of a polyimide-etalon transducer and demonstrate imaging with an array configuration alternative to our previous study.

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Background: Accumulating evidence documents the initiation of diverse physiologic and biochemical responses subsequent to an oral glucose load.

Objectives: We sought to evaluate the extent to which acute hyperglycemia, resulting from a 50-gram glucose load, contributes to changes in maternal plasma concentrations of advanced glycation end products (AGEs), a heterogeneous group of molecules formed from the non-enzymatic reaction of reducing sugars with free amino groups of proteins, lipids, and nucleic acids.

Methods: Blood specimens were collected from each participant in mid-pregnancy using standard procedures before and after a 50-gram oral glucose load.

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In this work, we have designed, fabricated, and tested an all-optical ultrasound transducer by integrating a photoabsorptive polyimide thin film into a Fabry-Pérot (etalon) high-frequency receiver. A 5-ns UV pulse was used for thermoelastic ultrasound generation in the polyimide film, and the transmission had a maximum amplitude of 4.3 MPa centered at 27 MHz with a fractional bandwidth of 107%.

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Background: Conventional liquid-handling devices were employed, along with an improved punching device, to semi-automate dried blood spot (DBS) extraction of alprazolam, α-hydroxyalprazolam and midazolam from human whole blood. Liquid-handling devices were used to add internal standard to the DBS cards and to extract the analytes from the DBS, in order to be analyzed by HPLC-MS/MS.

Results: The technique was shown to be accurate (±12.

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Background: Two ESI-LC-MS/MS methods were validated for the quantitative analysis of loxapine, amoxapine, 7-OH-loxapine, 8-OH-loxapine and loxapine N-oxide in human K(2)EDTA plasma. Cation-exchange solid-phase extraction (SPE) was used to extract loxapine, amoxapine and the two hydroxylated metabolites, and organic precipitation was used to quantify loxapine N-oxide.

Results: Both methods were shown to be accurate (±13%), intra-assay precision was less than 15%, and inter-assay precision was less than 10% in all instances across the entire dynamic range of the assays (0.

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Background: Dried matrix spot techniques were employed to validate an HPLC-MS/MS assay for the determination of dexamethasone in clear Yorkshire pig synovial fluid using 15 µl of sample. We have adopted the term dried matrix spot to indicate that the techniques used for dried blood spots can be applied to nonblood matrices. The dried matrix spot method employs a color-indicating process developed at Alturas Analytics that enhances the ability to analyze transparent fluids spotted onto collection paper by allowing the analyst to visually verify the location of the dried sample spot.

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Photoacoustic imaging endoscope.

Annu Int Conf IEEE Eng Med Biol Soc

April 2010

We currently present a design concept for a photoacoustic imaging endoscope as well as some preliminary experimental results. The device is based on the generation of acoustic waves in tissue by short laser pulses and the sensing of these waves with a thin, optical Fabry-Pérot etalon. The entire device is designed to be mounted on the tip of a needle to deliver high-resolution photoacoustic imaging for minimally-invasive clinical applications such as diagnosing kidney disease and guiding laparoscopic surgery.

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Uranyl ions [UO(2)](2+) in aqueous nitric acid can be extracted into supercritical CO(2) (sc-CO(2)) by using an imidazolium-based ionic liquid with tri-n-butyl phosphate (TBP) as a complexing agent. The transfer of uranium from the ionic liquid to the supercritical fluid phase was monitored by UV/Vis spectroscopy using a high-pressure fiber-optic cell. The form of the uranyl complex extracted into the sc-CO(2) phase was identified to be [UO(2)(NO(3))(2)(TBP)(2)].

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The detection and identification of 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and pentaerythritol tetranitrate (PETN) vapors have proven to be difficult and challenging due to the low vapor pressures of these high explosives. Detecting higher vapor pressure impurity compounds found in TNT and possible tagging agents mandated to be added to plastic explosives (RDX and PETN) would allow for easier vapor detection. The higher vapor pressure nitro compounds of interest are considered to be non-fluorescent; however, once reduced to their amino analogs, they have relatively high quantum yields.

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At six months after brain injury, about 65% of stroke survivors have been shown to be unable to incorporate the affected hand into activities of daily living (ADL). Using a reliable Brain-Machine-Interface (BMI) together with Neural Electronic Stimulation (NES) is a possible solution for the restoration of hand function in severely impaired hemiparetic stroke survivors. However, discoordination, i.

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The detection of explosive material is at the forefront of current analytical problems. A detection method is desired that is not restricted to detecting only explosive materials, but is also capable of identifying the origin and type of explosive. It is essential that a detection method have the selectivity to distinguish among compounds in a mixture of explosives.

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Nitroaromatics (such as dinitrotoluene, trinitrotoluene, and nitrobenzene) found in explosive vapors from buried landmines can be reduced to aminoaromatics by a novel process involving Pd metal nanocatalysts prepared in supercritical fluid carbon dioxide and supported on multi-walled carbon nanotubes. These aminoaromatics are fluorescent and, if desired, the fluorescence yield can be increased and the fluorescence maxima shifted further toward the red by reaction with appropriate derivatizing agents such as fluorescamine. Corrected spectra for these chemicals and their derivatives are included.

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Objective: To show that resuscitation from hypothermic, hemorrhagic shock using 65 degrees C intravenous fluid results in a more rapid return to euthermia compared with 40 degrees C intravenous fluid, without significant endothelial or hemolytic injury.

Design: Fourteen anesthetized beagles (10-12 kg) were cooled to a core temperature of 30 degrees C and hemorrhaged to a mean arterial pressure of 40 to 45 mm Hg for 30 minutes. The animals were randomized to receive either 65 degrees C or 40 degrees C intravenous fluid through a specially designed catheter at a rate of 80% of their blood volume per hour until euthermic (37 degrees C) or for 2 hours.

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Background: The infusion of warm intravenous fluid (IVF) is a simple and effective method used to maintain or restore core body temperature. At present, 40 degrees C is believed to be the highest temperature that can be safely administered. There is concern that temperatures greater than 40 degrees C may harm blood cells.

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Background: To demonstrate the safety and efficacy of 65 degrees C (149 degrees F) centrally administered intravenous fluid (CIVF) compared to conventional 40 degrees C (104 degrees F) CIVF in the treatment of hypothermia.

Method: Ten beagles (9-13 kg) were prospectively randomized to receive 65 degrees C or 40 degrees C CIVF. They were anesthetized and data were collected at baseline, during hypothermia, and after 1 and 2 hours of rewarming.

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Study Objective: To study the relationship between a trauma center per diem charges and medicare DRG reimbursement.

Design: Retrospective comparison of charges ($630/day, $1500/ICU day) and hypothetical DRG reimbursement using medical records ICD-9 N and P codes and version 5.0 of grouper.

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Study Objective: To study the relationship between a trauma center per diem charges and medicare DRG reimbursement.

Design: Retrospective comparison of charges ($630/day, $1500/ICU day) and hypothetical DRG reimbursement using medical records ICD-9 N and P codes and version 5.0 of grouper.

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The efficacy and safety of very hot (65 degrees C/149 degrees F) intravenous fluid (IVF) were compared with those of conventional warm (38 degrees C/100.4 degrees F) IVF in the treatment of hypothermia. Eight anesthetized beagles (11-20 kg) were studied.

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Although toxicology screening is often used when treating trauma patients, its utility and significance remain controversial. Data from 623 toxicology screens performed in urban trauma center patients with mental status alterations are reported. The study patients were predominantly black and male, with a mean age of 32 (+/- 22) years.

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We studied the influence of hospital bypass on prehospital times and Level 1 trauma patient survival. During the nine-month study period, 251 Level 1 trauma patients were transported to the Cook County Hospital trauma unit by Chicago Fire Department (CFD) paramedics. The prehospital times and survival rates in the 203 (81%) patients who arrived with vital signs were analyzed.

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Previous reports from this hospital documented a splenic preservation rate of 50% (18/36) in adults after blunt and penetrating trauma. Recently (January through December 1984), use of an absorbable mesh helped to attain a 67% (22/33) salvage rate. The mesh is applied in such a fashion that it acts by tamponade.

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