Anti-adhesive effects of Budesonide combined with spraygel in a cecal abrasion model: an experimental study

Many methods have been described for preventing or reducing postoperative adhesions. In this work, we evaluated the effectiveness of Budesonide in combination with SprayGel in a reducing postoperative adhesion in rats as the model. Cecal abrasion was achieved in 60 male Sprague-Dawley rats, by brushing and by applying 70% alcohol. The rats were separated into six groups and treated with six solutions (Group I – saline; II – Budesonide 50?μg; III – Budesonide 250?μg; IV – SprayGel; V and VI – SprayGel?+?Budesonide 50 and 250?μg). Serum Budesonide, glucose, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and blood urea nitrogen levels were measured at postoperative day (POD) 2 and 14. The rats were killed on POD 14, and intra-abdominal adhesion formation was scored. Histopathological samples were obtained from the cecum and terminal ileum to evaluate microscopic adhesion formation. Our results showed that Group VI had both the minimum macroscopic adhesion score and the minimum microscopic score. All other groups had significantly lower microscopic adhesion scores than Group I. However, there was no statistical significance among any other groups. Serum AST levels of Group III were significantly higher than in Groups I, II, IV, and V (p?<?0.046). Serum AST levels of Group III on POD 14 were also significantly higher than that of all other groups (p?<?0.02). On POD 14, there was no Budesonide in the sera of Groups II and V. However, Groups III and VI had trace amounts of Budesonide (0.009 and 0.007?μg, respectively). In conclusion, we have showed that the effect of Budesonide is dosedependent. Both anti-adhesive and hepatotoxic side effects of Budesonide increased as the dose increased. Combining Budesonide with SprayGel synergistically increased the anti-adhesive benefits and prevented hepatotoxicity from the slower release of Budesonide.     

Large-Area (over 50 cm × 50 cm) Freestanding Films of Colloidal InP/ZnS Quantum Dots

We propose and demonstrate the fabrication of flexible, freestanding films of InP/ZnS quantum dots (QDs) using fatty acid ligands across very large areas (greater than 50 cm × 50 cm), which have been developed for remote phosphor applications in solid-state lighting. Embedded in a poly(methyl methacrylate) matrix, although the formation of stand-alone films using other QDs commonly capped with trioctylphosphine oxide (TOPO) and oleic acid is not efficient, employing myristic acid as ligand in the synthesis of these QDs, which imparts a strongly hydrophobic character to the thin film, enables film formation and ease of removal even on surprisingly large areas, thereby avoiding the need for ligand exchange. When pumped by a blue LED, these Cd-free QD films allow for high color rendering, warm white light generation with a color rendering index of 89.30 and a correlated color temperature of 2298 K. In the composite film, the temperature-dependent emission kinetics and energy transfer dynamics among different-sized InP/ZnS QDs are investigated and a model is proposed. High levels of energy transfer efficiency (up to 80%) and strong donor lifetime modification (from 18 to 4 ns) are achieved. The suppression of the nonradiative channels is observed when the hybrid film is cooled to cryogenic temperatures. The lifetime changes of the donor and acceptor InP/ZnS QDs in the film as a result of the energy transfer are explained well by our theoretical model based on the exciton-exciton interactions among the dots and are in excellent agreement with the experimental results. The understanding of these excitonic interactions is essential to facilitate improvements in the fabrication of photometrically high quality nanophosphors. The ability to make such large-area, flexible, freestanding Cd-free QD films pave the way for environmentally friendly phosphor applications including flexible, surface-emitting light engines.     

High frequency performance of individual and arrays of single-walled carbon nanotubes

We have studied the high frequency performance limits of single-walled carbon nanotube (SWNT) transistors in the diffusive transport regime limited by the acoustic phonon scattering. The relativistic band structure of single-walled carbon nanotubes combined with the acoustic phonon scattering provides an analytical model for the charge transport of the radio frequency transistors. We were able to obtain the intrinsic high frequency performance such as the cut-off frequency and the linearity of the SWNT transistors. We have extended our model to include transistors based on arrays of SWNTs. The effect of electrostatic screening in a dense array of SWNTs on the cut-off frequency is studied.     

3-D imaging of large scale buried structure by 1-D inversion ofvery early time electromagnetic (VETEM) data

A simple and efficient method for large scale three-dimensional (3D) subsurface imaging of inhomogeneous background is presented. One-dimensional (1D) multifrequency distorted Born iterative method (DBIM) is employed in the inversion. Simulation results utilizing synthetic scattering data are given. Calibration of the very early time electromagnetic (VETEM) experimental waveforms is detailed along with major problems encountered in practice and their solutions. This discussion is followed by the results of a large scale application of the method to the experimental data provided by the VETEM system of the U.S. Geological Survey. The method is shown to have a computational complexity that is promising for on-site inversion     

Cognitive stimulation and problem presentation in idea-generating groups.

One technique that may facilitate group brainstorming is decomposition of the task so that categories of the problem are considered one at a time rather than simultaneously (A. R. Dennis, J. S. Valacich, T. Connolly, & B. E. Wynne, 1996). Two studies examined this possibility for both solitary and interactive brainstorming in which major categories of a brainstorming problem were presented simultaneously or sequentially. In the 1st study, participants in the sequential presentation condition generated more ideas than did those in the simultaneous condition in both the individual and the group conditions. In the 2nd study, individuals exposed to either a high number or low number of idea categories demonstrated enhanced performance. Simulations of the data demonstrated that the results were consistent with an associative memory model of the idea generation process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quarantine region scheme to mitigate spam attacks in wireless-sensor networks

The quarantine region scheme (QRS) is introduced to defend against spam attacks in wireless sensor networks where malicious antinodes frequently generate dummy spam messages to be relayed toward the sink. The aim of the attacker is the exhaustion of the sensor node batteries and the extra delay caused by processing the spam messages. Network-wide message authentication may solve this problem with a cost of cryptographic operations to be performed over all messages. QRS is designed to reduce this cost by applying authentication only whenever and wherever necessary. In QRS, the nodes that detect a nearby spam attack assume themselves to be in a quarantine region. This detection is performed by intermittent authentication checks. Once quarantined, a node continuously applies authentication measures until the spam attack ceases. In the QRS scheme, there is a trade-off between the resilience against spam attacks and the number of authentications. Our experiments show that, in the worst-case scenario that we considered, a not quarantined node catches 80 percent of the spam messages by authenticating only 50 percent of all messages that it processes.     

Detection of buried targets using a new enhanced very early timeelectromagnetic (VETEM) prototype system

In this paper, numerical simulations of a new enhanced very early time electromagnetic (VETEM) prototype system are presented, where a horizontal transmitting loop and two horizontal receiving loops are used to detect buried targets, in which three loops share the same axis and the transmitter is located at the center of receivers. In the new VETEM system, the difference of signals from two receivers is taken to eliminate strong direct-signals from the transmitter and background clutter and furthermore to obtain a better SNR for buried targets. Because strong coupling exists between the transmitter and receivers, accurate analysis of the three-loop antenna system is required, for which a loop-tree basis function method has been utilized to overcome the low-frequency breakdown problem. In the analysis of scattering problem from buried targets, a conjugate gradient (CG) method with fast Fourier transform (FFT) is applied to solve the electric field integral equation. However, the convergence of such CG-FFT algorithm is extremely slow at very low frequencies. In order to increase the convergence rate, a frequency-hopping approach has been used. Finally, the primary, coupling, reflected, and scattered magnetic fields are evaluated at receiving loops to calculate the output electric current. Numerous simulation results are given to interpret the new VETEM system. Comparing with other single-transmitter-receiver systems, the new VETEM has better SNR and ability to reduce the clutter     

Experimental study of horizontal ground source heat pump performance for mild climate in Turkey

The aim of this study is to evaluate the performance of horizontal GSHP by considering various system parameters for winter climatic condition of Bursa, Turkey. For this purpose, a previously used experimental facility on cooling cycle [Coskun S, Pulat E, Unlu K, Yamankaradeniz R. Experimental performance investigation of a horizontal ground source compression refrigeration machine. International Journal of Energy Research 2008; 32: 44–56] was modified for the heating cycle. Soil thermal conductivity estimation was expanded and discussed. Preliminary numerical temperature distribution around GHE pipes was obtained. Tests were performed under laboratory conditions for space heating from December 2004 to March 2005. Variations of entering and leaving antifreeze solution temperatures, extracted heat from ground and rejected heat to the test room, super heat rate in evaporator and subcooling rate in condenser, total power consumption and coefficient of performance (COP) values for both the entire system and only heat pump unit (HPU) were obtained. Effect of outdoor temperature on system capacities and COP values with respect to outdoor air and mean soil temperatures were also presented. The COP of the entire system and HPU lie between 2.46–2.58 and 4.03–4.18, respectively. GSHP system was compared to conventional heating methods in the economical analysis and it was shown that the GSHP system is more cost effective than the all other conventional heating systems.     

Optofluidic fluorescent imaging cytometry on a cell phone

Fluorescent microscopy and flow cytometry are widely used tools in biomedical sciences. Cost-effective translation of these technologies to remote and resource-limited environments could create new opportunities especially for telemedicine applications. Toward this direction, here we demonstrate the integration of imaging cytometry and fluorescent microscopy on a cell phone using a compact, lightweight, and cost-effective optofluidic attachment. In this cell-phone-based optofluidic imaging cytometry platform, fluorescently labeled particles or cells of interest are continuously delivered to our imaging volume through a disposable microfluidic channel that is positioned above the existing camera unit of the cell phone. The same microfluidic device also acts as a multilayered optofluidic waveguide and efficiently guides our excitation light, which is butt-coupled from the side facets of our microfluidic channel using inexpensive light-emitting diodes. Since the excitation of the sample volume occurs through guided waves that propagate perpendicular to the detection path, our cell-phone camera can record fluorescent movies of the specimens as they are flowing through the microchannel. The digital frames of these fluorescent movies are then rapidly processed to quantify the count and the density of the labeled particles/cells within the target solution of interest. We tested the performance of our cell-phone-based imaging cytometer by measuring the density of white blood cells in human blood samples, which provided a decent match to a commercially available hematology analyzer. We further characterized the imaging quality of the same platform to demonstrate a spatial resolution of ~2 μm. This cell-phone-enabled optofluidic imaging flow cytometer could especially be useful for rapid and sensitive imaging of bodily fluids for conducting various cell counts (e.g., toward monitoring of HIV+ patients) or rare cell analysis as well as for screening of water quality in remote and resource-poor settings.