Hyperfine fields and magnetoelastic surface effects in Fe72Cu1.5Nb4Si13.5B9 nanocrystalline alloy

In this work hyperfine fields of two-phase nanocrystalline Fe72Cu1.5Nb4Si13.5B9 alloys were studied in order to verify the existence of surface effects. To obtain a series of nanocrystalline samples with small grains of different sizes, a special non- -isothermal annealing procedure of an initially amorphous ribbon was applied. In the case of samples with a significant amount of crystallites, a high field (about 27.5 T) component of continuous part of the hyperfine field distribution was found that could be attributed to boundary regions between the grains and rest of the sample. The existence of the surface effects was confirmed in the magnetostrictive experimen

Embracing the polypill as a cardiovascular therapeutic: is this the best strategy?

INTRODUCTION: Cardiovascular disease (CVD) is an important cause of mortality and morbidity worldwide. CVD morbidity and mortality are associated with significant financial costs related to hospitalization, medication, and lost productivity. The concept of the 'polypill' for the reduction of cardiovascular risk was proposed in 2000. A polypill is a fixed combination of drugs in a single tablet or capsule. The initial polypill consisted of three different classes of antihypertensive drugs (each at half dose), in addition to aspirin, a statin, and folic acid. The challenge today is to produce polypills containing drugs with established efficacy and complementary actions. Areas covered: The authors provide their expert perspectives on the polypill and consider the randomized clinical trials that have evaluated the safety, efficacy, adherence, and cost-effectiveness of polypills. Expert opinion: The polypill makes prescribing easier by reducing the need for complex treatment algorithms and dose titration. It also appears to be cost-effective. However, there are several issues that need to be addressed before the polypill can be used routinely. A single polypill formulation may not be suitable for all patients. It may be necessary to develop several types of polypill to meet the needs of different patient groups

A microfluidic device with fluorimetric detection for intracellular components analysis

An integrated microfluidic system that coupled lysis of two cell lines: L929 fibroblasts and A549 epithelial cells, with fluorescence-based enzyme assay was developed to determine β-glucocerebrosidase activity. The microdevice fabricated in poly(dimethylsiloxane) consists of three main parts: a chemical cell lysis zone based on the sheath flow geometry, a micromeander and an optical fibers detection zone. Unlike many methods described in literature that are designed to analyse intracellular components, the presented system enables to perform enzyme assays just after cell lysis process. It reduces the effect of proteases released in lysis process on determined enzymes. Glucocerebrosidase activity, the diagnostic marker for Gaucher’s disease, is the most commonly measured in leukocytes and fibroblasts using 4-methylumbelliferyl-β-D-glucopyranoside as synthetic β-glucoside. The enzyme cleavage releases the fluorescent product, i.e. 4-methylumbelliferone, and its fluorescence is measured as a function of time. The method of enzyme activity determination described in this paper was adapted for flow measurements in the microdevice. The curve of the enzymatic reaction advancement was prepared for three reaction times obtained from application of different flow rates of solutions introduced to the microsystem. Afterwards, determined β-glucocerebrosidase activity was recalculated with regard to 105 cells present in samples used for the tests. The obtained results were compared with a cuvette-based measurements. The lysosomal β-glucosidase activities determined in the microsystem were in good correlation with the values determined during macro-scale measurements

Miniaturized device for a cell lysis process

Single-cell studies are crucial for gaining knowledge on complexity of intracellular processes. In many cases, carrying researches into cell ingredients must be proceeded by a lysis process. Cell lysis leads to disintegration of the plasma membrane which is the barrier separating cell contents from the environment. However, investigations at the cellular level would not be possible without proper miniaturized tools, which offer many advantages as low reagents consumption, short reaction time, integration, automation or versatility. The goal of this work was to design and develop a microfluidic chip for a chemical cell lysis process. The geometry of a microsystem presented is based on the hydrodynamic focusing of a cell suspension stream. Applying non-denaturing cell lysis buffer enables to analyze released cell ingredients during next steps of investigations

Surface Effects in Fe-Based Nanocrystalline Alloys

The microstructural and Mossbauer investigations of FeZrBCu nanocrystalline alloy are presented. The results obtained indicate that fine bcc-Fe grains do possess identifiable surface properties which arise from the symmetry restriction at grain boundary

Microfluidic devices — application in anticancer studies

A rapidly growing pharmaceutical industry requires faster and more efficient ways to find and test new drugs. One of the new method for cell culture and examining the toxic effects of drugs is application of microfluidic systems. They provide new types of microenvironments and new methods for investigation of anticancer therapy. The use of microsystems is a solution that gives the opportunity to reduce not only cost and time, but also a number of tests on animals. In this paper we present designed and fabricated hybrid microfluidic systems which are applicable for cell culture, cell based cytotoxicity assays and photodynamic therapy procedures. Polydimethylsiloxane (PDMS) and sodium glass were used for fabrication of microdevices. The designed geometry of the microdevices includes cell culture microchambers and a concentration gradient generator (CGG). The CGG enables to obtain diff erent concentrations of tested drugs in a single step, which is a significant simplification of cytotoxicity assay procedure. In the designed microsystems three various cell lines (normal and carcinoma) were cultured and analyzed