Balloon occlusion retrograde transvenous obliteration of gastric varices in two non-cirrhotic patients with portal vein thrombosis

This report describes two non-cirrhotic patients with portal vein thrombosis who underwent successful balloon occlusion retrograde transvenous obliteration (BRTO) of gastric varices with a satisfactory response and no complications. One patient was a 35-year-old female with a history of Crohn's disease, status post-total abdominal colectomy, and portal vein and mesenteric vein thrombosis. The other patient was a 51-year-old female with necrotizing pancreatitis, portal vein thrombosis, and gastric varices. The BRTO procedure was a useful treatment for gastric varices in non-cirrhotic patients with portal vein thrombosis in the presence of a gastrorenal shunt

Magnetic forces for surface-based bioanalysis in microfluidic devices

Biochemical analysis is a critical part of clinical diagnostics, forensic science and environmental monitoring. Typically, this form of analysis involves the use of bioanalytical procedures which are extremely sensitive and highly specific. However, such assays often involve many different reaction and washing steps, which means that a single analysis could take hours or even days to perform. There is an urgent demand for high through-put analysis systems that are rapid, simple to use and can be utilised in the field or at the point-of-care. Microfluidic technology has gone some way to producing such systems, however many of the current devices still incorporate batch methods of analysis, which are still time consuming or do not integrate all steps of the analysis on one device.Two aspects of particle handling utilising magnetic forces were investigated. 1) The use of single magnetic particles as mobile solid-supports in a continuous flow system for bioanalysis. 2) The use of diamagnetic repulsion forces for label-free on-chip particle handling.For the continuous flow system, a magnetic particle type was selected from eight commercially available brands of particles and characterised using on and off-chip measurements. Dynabead M-270 particles were ultimately used as mobile solidsupports for performing entire bioanalytical processes in continuous flow, for the first time. This was achieved by generating multiple laminar flow streams along the length of a rectangular chamber and applying a magnetic field gradient perpendicular to flow. Each reagent stream contained reagents for a molecular binding assay and functionalised magnetic particles were deflected across the width of the chamber. As the particles were deflected through reagent streams, washing and reaction steps were performed on the surface of the particle in one operation in continuous flow. The system was used to perform a one-step streptavidin - biotin binding assay with an LOD of 20 µg mL-1 , a two-step mouse IgG immunoassay with an LOD of 0.1 µg mL-1 and a qualitative sandwich immunoassay for C-reactive protein (CRP). All three procedures were performed within one minute with no manual intervention.For the diamagnetic repulsion forces for label-free particle handling, 10 µm polystyrene particles were trapped into plugs on a glass capillary by suspending them in a paramagnetic solution and creating an area of high magnetic field gradient between two magnets. Particles were repelled by the field and formed a plug upstream from the magnets. The system was used to simultaneously perform positive and negative controls on a sample of fluorescently labelled biotin using two plugs; one containing streptavidin functionalised polystyrene particles and one containing plain polystyrene particles. In addition, diamagnetic repulsion was used to deflect polystyrene particles from flow inside a square deflection chamber. A particle mixture of 5 µm and 10 µm particles were separated into different exits at a flow rate of 20 µLh-1 based on the difference in their volume, termed free-flow diamagnetophoresis. Potential applications include label-free cell manipulation

Diamagnetic repulsion of particles for multilaminar flow assays

© The Royal Society of Chemistry. We demonstrate diamagnetic repulsion forces for performing continuous multilaminar flow assays on particles based on their intrinsic properties and with a simple setup. The platform could be applied to sandwich assays on polystyrene particles, and to cell-based assays via their suspension in biologically benign magnetic media

On the Content of Polynomials Over Semirings and Its Applications

In this paper, we prove that Dedekind-Mertens lemma holds only for those semimodules whose subsemimodules are subtractive. We introduce Gaussian semirings and prove that bounded distributive lattices are Gaussian semirings. Then we introduce weak Gaussian semirings and prove that a semiring is weak Gaussian if and only if each prime ideal of this semiring is subtractive. We also define content semialgebras as a generalization of polynomial semirings and content algebras and show that in content extensions for semirings, minimal primes extend to minimal primes and discuss zero-divisors of a content semialgebra over a semiring who has Property (A) or whose set of zero-divisors is a finite union of prime ideals. We also discuss formal power series semirings and show that under suitable conditions, they are good examples of weak content semialgebras.Comment: Final version published at J. Algebra Appl., one reference added, three minor editorial change

On-chip determination of C-reactive protein using magnetic particles in continuous flow

We demonstrate the application of a multilaminar flow platform, in which functionalized magnetic particles are deflected through alternating laminar flow streams of reagents and washing solutions via an external magnet, for the rapid detection of the inflammatory biomarker, C-reactive protein (CRP). The two-step sandwich immunoassay was accomplished in less than 60 s, a vast improvement on the 80−300 min time frame required for enzyme-linked immunosorbent assays (ELISA) and the 50 min necessary for off-chip magnetic particle-based assays. The combination of continuous flow and a stationary magnet enables a degree of autonomy in the system, while a detection limit of 0.87 μg mL−1 makes it suitable for the determination of CRP concentrations in clinical diagnostics. Its applicability was further proven by assaying real human serum samples and comparing those results to values obtained using standard ELISA tests

Large eddy simulations and direct numerical simulations of high speed turbulent reacting flows

This research is involved with the implementations of advanced computational schemes based on large eddy simulations (LES) and direct numerical simulations (DNS) to study the phenomenon of mixing and its coupling with chemical reactions in compressible turbulent flows. In the efforts related to LES, a research program was initiated to extend the present capabilities of this method for the treatment of chemically reacting flows, whereas in the DNS efforts, focus was on detailed investigations of the effects of compressibility, heat release, and nonequilibrium kinetics modeling in high speed reacting flows. The efforts to date were primarily focussed on simulations of simple flows, namely, homogeneous compressible flows and temporally developing hign speed mixing layers. A summary of the accomplishments is provided

Permit market auctions with allowance reserves

This article investigates pollution permit auctions that incorporate allowance reserves. In these auctions the sale of a fixed quantity of permits is supplemented by an additional permit reserve. This reserve automatically releases permits if a sufficiently high price is triggered. The main justifications for implementing an allowance reserve are to reduce price volatility as well as assisting in cost containment. We show—paradoxically—that incorporating an allowance reserve into a permit auction can decrease firms’ payoffs, increase the clearing price, and increase compliance costs. This has implications for all major cap-and-trade markets, including the US Regional Greenhouse Gas Initiative

A quantum heat exchanger for nanotechnology

In this paper, we design a quantum heat exchanger which converts heat into light on relatively short quantum optical time scales. Our scheme takes advantage of heat transfer as well as collective cavity-mediated laser cooling of an atomic gas inside a cavitating bubble. Laser cooling routinely transfers individually trapped ions to nano-Kelvin temperatures for applications in quantum technology. The quantum heat exchanger which we propose here might be able to provide cooling rates of the order of Kelvin temperatures per millisecond and is expected to find applications in micro- and nanotechnology

Combination Therapies in Ophthalmology: Implications for Intravitreal Delivery

Most pathological processes involve complex molecular pathways that can only be modified or blocked by a combination of medications. Combination therapy has become a common practice in medicine. In ophthalmology, this approach has been used effectively to treat bacterial, fungal, proliferative/neoplastic, and inflammatory eye diseases and vascular proliferation. Combination therapy also encompasses the synergistic effect of electromagnetic radiation and medications. However, combination therapy can augment inherent complications of individual interventions, therefore vigilance is required. Complications of combination therapy include potential incompatibility among compounds and tissue toxicity. Understanding these effects will assist the ophthalmologist in his decision to maximize the benefits of combination therapy while avoiding an unfavorable outcome