Analytic Formulas for the Clinical Issues of a UV-Light-Activated Corneal Crosslinking Device

Modeling the critical issues of the dynamics of UV-light-initiated crosslinking of corneal collagen including the new safety criteria, crosslinking time and the efficacy. A coupled dynamic equations is numerically solved and analytic formulas are derived for three critical parameters: the safety dose (E*), the cross linking time (T*) and the efficacy defined by the increase of corneal stiffness (S). The critical issues of corneal crosslinking is explored by nine parameters: the three extinction coefficients, concentration and diffusion depth of the riboflavin solution, the UV light dose, irradiation duration, the cytotoxic energy threshold of endothelial cells and the corneal thickness.

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Preliminary Development of a Magnetically Assisted Test Strip (MATS) Cartridge and Fluorescent DNA Aptamer-Magnetic Bead Quantum Dot Sandwich Assays for Multiplexed Food Safety Applications

Preliminary development of a simple mesofluidic multi-channel plastic cartridge with underlying external magnet to drag DNA aptamer-coated paramagnetic beads through fluids in the channels while developing a sandwich assay with quantum dot-conjugated reporter aptamers is described. 

This approach is superior to traditional lateral flow test strips in several ways including: 1) the ability to control the speed of lateral flow inthe channel versus conventional nitrocellulose analytical membranes with fixed wicking times. 2) The use of aptamers for potentially greater affinity and consistency from batch-to-batch versus comparable antibodies. 3) Superior fluorescence efficiency and intensity provided by quantum dots versus conventional fluorescent dyes and 4) the ability to multiplex based on the various colored emissions of different sized quantum dots when excited with a single ultra violet source. Development of the system from concept to prototype is described along with illustration of sensitive system performance for several food safety-related targets. The system is also clearly adaptable to rapid multiplex detection and sensitive quantitation of clinical biomarkers, drugs, environmental, veterinary or other target analytes.

New Insights on the Cardiovascular Inflammation due to Multi Layered Plaque Accumulation

Cellular functions such as the maintenance of homoeostasis are regulated by shear forces sensed by endothelial cells. The endothelial cells sense local changes by absorbing the stress and produces signals that either transduce chemical responses or transmit the same to regulate the cellular activity. Certain parts of our body are prone to plaque phenotype and they rupture due to plaque accumulation. The blood cells that are smaller in size under the normal conditions grow in size to block the blood flow through the arteries. Severe stenosis and the local particle concentration leads to high cardio vascular inflammation.

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Solid-phase Immuno Radio Metric Assay (IRMA) of 25-hydroxy Vitamin D and Displacement from Serum Binding Proteins for Resource-limited Settings

The development of a solid-phase immune radiometric assay to satisfy the pressing need for a simple yet effective method for measuring 25-hydroxyvitamin D[25(OH)D] in a serum and thus more suited to routine use in clinical biochemical laboratories. The aim of this study was not to compare our home made with commercially available method but tested for general assay performance, including homemade polyclonal antibody specificity. Methods: We used our home made radioiodine (125I)-based IRMA kit for the detection of 25(OH)D. 

It is based upon, non-competitive displacement agents which enable effective separation of vitamin D metabolites from binding proteins to enable the amount of vitamin D metabolites to be measured, without competing with the proteins or requiring its solvent extraction from the serum.Our package called: “cgea 25(OH)D-irma” is analytically, all qualities we expect from a good medical test kit, with a precision of coefficients below 13%as well as intra-series that in inter-series and inter-batch accuracy with a linearity estimated at 0.8ng/ml and good stability of the radio labeled trace(60 days). Conclusion: Simplification of the methods for extraction and separation has been a key feature in the improvement of assays for vitamin D in Democratic Republic of Congo. 

Cardiopulmonary Resuscitation as a Graduation Requirement for Biomedical Engineering Students

At the end of a mountain road in Austria during the summer of 2003, I waited for a boat with my family on a dock at a large lake. Suddenly I saw a man fall to the sidewalk. His skin had turned that ashen blue color, and it was clear to me that he was in cardiac arrest. There was a crowd of more than 75 persons just standing and looking at him. I knew what to do when there was no detectable pulse or breathing. Cardio-Pulmonary Resuscitation (CPR) chest compressions were started immediately. 

His skin color returned to nearly normal. After a few minutes, a single bystander came up and said they knew how to do breaths. At that time, recommendations were for intermittent breathing as well as chest compressions. The stricken person made it alive to the EMS vehicle that took nearly 30 minutes to arrive. While I do not know the eventual outcome, I do know he was successfully resuscitated using an Automated External Defibrillator (AED). Furthermore with the quick application of CPR, he likely had a full recovery. Unfortunately, from the crowd response at that time, there were not enough people trained to act in this emergency situation where seconds really count.

A Multi-Layer Non-Newtonian Model of Cardiovascular Inflammation

We found that such locations are correlated to the vulnerable plaque phenotype, which is prone to rupture. Our results demonstrate that at locations of high particle concentration, blood particles change the shear stress distribution and magnitude. 

Therefore, the non-Newtonian blood flow assumption provides new insights in the characterisation of plaque built up. These results are combined to in-vitro experiments that suggest the influence of blood particles in the activity of cytokines. An unbalance in pro and anti-inflammatory cytokines has been associated to an increase in inflammation and, consequently, in the volume of plaques forming.