Droplet-based logic gates simulation of viscoelastic fluids under electric field.

Nano and microfluidic technologies have shown great promise in the development of controlled drug delivery systems and the creation of microfluidic devices with logic-like functionalities. Here, we focused on investigating a droplet-based logic gate that can be used for automating medical diagnostic assays. This logic gate uses viscoelastic fluids, which are particularly relevant since bio-fluids exhibit viscoelastic properties. The operation of the logic gate is determined by evaluating various parameters, including the Weissenberg number, the Capillary number, and geometric factors. To effectively classify the logic gates operational conditions, we employed a deep learning classification to develop a reduced-order model. This approach accelerates the prediction of operating conditions, eliminating the need for complex simulations. Moreover, the deep learning model allows for the combination of different AND/OR branches, further enhancing the versatility of the logic gate. We also found that non-operating regions, where the logic gate does not function properly, can be transformed into operational regions by applying an external force. By utilizing an electrical induction technique, we demonstrated that the application of an electric field can repel or attract droplets, thereby improving the performance of the logic gate. Overall, our research shows the potential of the droplet-based logic gates in the field of medical diagnostics. The integration of deep learning classification algorithms enables rapid evaluation of operational conditions and facilitates the design of complex logic circuits. Additionally, the introduction of external forces and electrical induction techniques opens up new possibilities for enhancing the functionality and reliability of these logic gates.

Sphenoid sinus barotrauma with intracranial air in sella turcica after diving.

We report the case of a diver who presented with air in the sella turcica after barotrauma to the sphenoid sinus during an ascent from a dive. To our knowledge, this is the first report of intracranial air after a barotrauma to the sphenoid sinus.

Unchanged incidence of diabetic nephropathy in Type 1 diabetes: a nation-wide study in Iceland.

AIMS: Diabetic nephropathy is an uncommon cause of end-stage renal disease in Iceland in contrast to most industrialized countries. The aim of this study was to examine the incidence of diabetic nephropathy in Iceland. METHODS: All patients diagnosed with Type 1 diabetes in Iceland before 1992 were studied retrospectively. Patients diagnosed before age 30, who were insulin dependent from the onset, were defined as having Type 1 diabetes. Diabetic nephropathy was defined as persistent proteinuria measured with a dipstick test (Albustix) on three consecutive clinic visits at least 2 months apart. Patients were followed to the end of year 1998, to their last recorded outpatient visit, or until death. The cumulative incidence of diabetic nephropathy was calculated with the Kaplan-Meier method and presented according to the duration of diabetes divided into 5-year intervals. RESULTS: A total of 343 patients with Type 1 diabetes were identified. The mean follow-up period was 20.2 +/- 11.4 (mean +/- sd) years. Only 9.3% of patients were lost to follow-up. Sixty-five patients developed diabetic nephropathy. The cumulative incidence was 22.6% at 20 years and levelled off at 40.3% after approximately 35 years of diabetes duration. No significant changes in cumulative incidence were observed over time. Mean glycated haemoglobin was 8.4% in patients with proteinuria and 7.8% in a group of patients without proteinuria that was matched for age, gender and duration of diabetes (P = 0.04). CONCLUSIONS: The cumulative incidence of diabetic nephropathy in Iceland is comparable with previously reported cumulative incidence rates and has remained unchanged. Glycaemic control was significantly better in patients without proteinuria.

Bilateral multifocal renal oncocytoma--a case report and literature review.

A case of bilateral multifocal renal oncocytoma is reported. The incidence, diagnosis and management of such tumors is discussed.

Low Reynolds Number Interactions between Colloidal Particles near the Entrance to a Cylindrical Pore.

The interaction between stable colloidal particles arriving at a pore entrance was studied using a numerical method for the case where the particle size is smaller than but of the same order as the pore size. The numerical method was adapted from a front-tracking technique developed for studying incompressible, multifluid flow by S. O. Unverdi and G. Tryggvason (J. Comp. Phys. 100, 25, 1992). The method is based on the finite difference solution of Navier-Stokes equation on a stationary, structured, Cartesian grid and the explicit representation of the particle-liquid interface using an unstructured grid that moves through the stationary grid. The simulations are in two dimensions, considering both deformable and nondeformable particles, and include interparticle colloidal interactions. The interparticle and particle-pore hydrodynamic interactions, which are very difficult to determine using existing analytical and semi-numerical, semi-analytical techniques in microhydrodynamics, are naturally accounted for in our numerical method and need not be explicity determined. Two- and three-particle motion toward a pore has been considered in our simulations. The simulations demonstrate how the competition between hydrodynamic forces and colloidal forces acting on particles dictate their flow behavior near the pore entrance. The predicted dependence of the particle flow behavior on the flow velocity and the ratio of pore size to particle size are qualitatively consistent with the experimental observations of V. Ramachandran and H. S. Fogler (J. Fluid Mech. 385, 129, 1999). Copyright 2000 Academic Press.

The osmotic migration of cells in a solute gradient.

The effect of a nonuniform solute concentration on the osmotic transport of water through the boundaries of a simple model cell is investigated. A system of two ordinary differential equations is derived for the motion of a single cell in the limit of a fast solute diffusion, and an analytic solution is obtained for one special case. A two-dimensional finite element model has been developed to simulate the more general case (finite diffusion rates, solute gradient induced by a solidification front). It is shown that the cell moves to regions of lower solute concentration due to the uneven flux of water through the cell boundaries. This mechanism has apparently not been discussed previously. The magnitude of this effect is small for red blood cells, the case in which all of the relevant parameters are known. We show, however, that it increases with cell size and membrane permeability, so this effect could be important for larger cells. The finite element model presented should also have other applications in the study of the response of cells to an osmotic stress and for the interaction of cells and solidification fronts. Such investigations are of major relevance for the optimization of cryopreservation processes.