On total internal reflection investigation of nanoparticles by integrated micro-fluidic system

We report on a novel sensor for characterization of nanoparticles colloidal suspensions. We employ a diffraction grating under total internal reflection for investigation of nanodisperse fluids passing through an integrated microfluidic channel. Dispersions containing polymeric, metallic, and ferromagnetic nanoparticles are studied. Using this device, we can accurately determine in real-time the specific refractive index for the nanoparticle suspension and the nanoparticle concentration. The nanoparticle concentrations can be calculated with a resolution of 0.3-0.5 wt% for polymeric nanoparticles, 0.03-0.05 wt% for metallic nanoparticles, and 0.05-0.1 wt% for ferromagnetic nanoparticles. This translates to an effective refractive index that can be determined with an accuracy of 7 x 10(-4) for the polymeric and 2 x 10(-4) for the metallic and ferromagnetic dispersions.     

Pharmacokinetics and pharmacodynamics of sibrafiban (Ro 48-3657), an orally active IIb/IIIa antagonist, administered alone or in combination with heparin, aspirin, and recombinant tissue-type plasminogen activator in beagles

OBJECTIVE: The study aimed to determine the effectiveness of prophylactic medical intervention in reducing the incidence of cystoid macular edema (CME) and the effectiveness of medical treatment for chronic CME after cataract surgery. DESIGN: The study design was a systematic review and meta-analysis of published reports of randomized clinical trials (RCTs). PARTICIPANTS: Sixteen RCTs involving 2898 eyes examining the effectiveness of medical prophylaxis of CME and 4 RCTs involving 187 eyes testing the effectiveness of medical treatment of chronic CME were used in the study. INTERVENTIONS: Medical prophylaxis of treatment (cyclo-oxygenase inhibitors or corticosteroids) versus control (placebo or active treatment) was performed. MAIN OUTCOME MEASURES: Incidence of angiographically diagnosed CME, incidence of clinically significant CME, and vision were measured. RESULTS: Thirty-six articles reported testing a prophylactic medical intervention for CME after cataract surgery. The incidence of CME varied extensively across studies and was related to the study design used. Summary odds ratios (OR) indicated that prophylactic intervention was effective in reducing the incidence of both angiographic CME (OR = 0.36; 95% confidence interval [CI] = 0.28-0.45) and clinically relevant CME (OR = 0.49; 95% CI = 0.33-0.73). There also was a statistically significant positive effect on improving vision (OR = 1.97; 95% CI = 1.14-3.41). A combination of the results of the four RCTs testing medical therapy for chronic CME indicated a treatment benefit in terms of improving final visual acuity by two or more Snellen lines (OR = 2.67; 95% CI = 1.35-5.30). Assessment of the quality of the 20 RCTs included in the meta-analyses indicated problems in the design, execution, and reporting of a number of trials. CONCLUSION: A combination of the results from RCTs indicates that medical prophylaxis for aphakic and pseudophakic CME and medical treatment for chronic CME are beneficial. Because most of the RCTs performed to date have problems related to quality, a well-designed RCT is needed to confirm this result, using clinical CME and vision as outcomes.     

Electron diffraction study of phase transformations of the compound CuSe

The transformations of the compound CuSe were investigated. At temperatures below 350°C the consecutive phase transitions CuSe→Cu_2?xSe→Cu₂Se were observed. Above 350°C decomposition of the CuSe into two phases, Cu₂Se and an f.c.c. phase with $\text{a=5.63}\text{A}\text{?}$, takes place. It was determined that the range of the lattice parameter a of the f.c.c. phase Cu_2?xSe is from 5.68 to 5.75Å and the existence ranges of the phases observed were evaluated. It was shown that the f.c.c. phase with $\text{a=5.63}\text{A}\text{?}$ is an independent phase.     

The synaptic release of dopamine in the striatum of rats during the acquisition of a passive avoidance conditioned reflex

To study the striatal synaptic dopamine release during passive avoidance behaviour the intracranial microdialysis technique combined with radioenzymatic assay method was used in Sprague-Dawley rats. It was shown that the acquisition of passive avoidance conditioning and an unescapable footshock led to delayed increases in striatal synaptic dopamine release.     

A phase II trial of weekly infusional 5-fluorouracil in combination with low-dose leucovorin in patients with advanced colorectal cancer

We examined 59 breast cancers for p53 and bcl-2 protein expression by immunohistochemistry. The results were correlated with Ki-67 immunostaining. p53-negativity was noted in 40 cases and the remaining 19 tumours were p53-positive. Thirty-six tumours showed strong expression of bcl-2 and in 23 no staining for this protein was observed. We found statistically significant reverse correlation between expression of p53 and bcl-2 in majority of carcinomas: 31 cases were bcl-2 positive and p53-negative, and 14 tumours were bcl-2-negative and p53-positive. Six carcinomas showed no nuclear staining for Ki-67 and in the remaining 53 the percent of cancer cells positive for Ki-67 ranged from 1 to 60 (mean: 14.6). In these 53 cases we found that bcl-2-positive tumours were characterized by lower proliferation than bcl-2-negative tumours, the mean value of Ki-67 immunostaining being 10.7% and 23.0%, respectively. p53-negative tumours showed lower proliferation than p53-positive tumours: mean Ki-67 index was 10.2% and 23.9%, respectively. We conclude that immunohistochemically detected p53 and bcl-2 proteins show a significant inverse relationship in majority of breast carcinomas and their expression correlates with tumour proliferation (Ki-67 immunostaining).     

Structure of bismuth films obtained using an array of identically oriented single-crystal bismuth islands preliminarily grown on a substrate

An array of identically oriented single-crystal bismuth islands formed on mica plates is used as a substrate to improve the structure of bismuth thin films grown by vacuum thermal evaporation. The array of islands is formed by the chemical etching of a single-crystal bismuth film 1 μm thick grown by floating-zone recrystallization under a coating. The structure of the obtained films is studied by X-ray diffraction, atomicforce microscopy, and electron backscatter diffraction scanning electron microscopy.     

Dependence of the surface morphology of ultrathin bismuth films on mica substrates on the film thickness

The results of studying the surface of 15- to 100-nm-thick bismuth films by atomic-force microscopy are reported. The near-linear character of the dependences of the average surface roughness and the average height of growth patterns on the film thickness is established. It is found that the average crystallite size increases, as the film thickness is increased. A slight dependence of the crystallite size on the film thickness is observed at thicknesses in the range of 27–70 nm.     

Deposition and dielectric properties of (Al2O3) x (TiO2)1−x thin films

The motivation for this study was to obtain an alloy system (Al₂O₃) _x (TiO₂)_1?x , that is thermodynamically stable, in direct contact with Si and possessing a high dielectric constant. In the present study, (Al₂O₃) _x (TiO)_1?x films were investigated. They were prepared by spin coating from a sol solution, with additional thermal annealing. The chemical composition and stoichiometry of the films was studied by X-ray photoelectron spectroscopy. For the electrical characteristics, MIS capacitors were fabricated. The determined relative dielectric constants were larger than the reported values for pure Al₂O₃, due to the presence of TiO₂.     

Development of a strategy of influenza virus separation based on pseudoaffinity chromatography on short monolithic columns

This research is devoted to the development and optimization of fine purification processes realized on short monolithic columns (CIM disks), using influenza vaccine and viruslike synthetic particles as model objects. The pseudoaffinity mode of liquid chromatography has been used as a tool for dynamic adsorption experiments. Viruslike particles, close to the dimensions of influenza viruses, were developed by means of main antigen of influenza viruses (hemeagglutinin) covalent binding to the outer aminated surface of synthetic latex particles. The natural receptor analogues of sialic acid were used as affinity ligands immobilized on the surface of the CIM disk by different ways to achieve a high adsorption capacity. Also, some other ligands were tested as possible candidates for virus capturing. The affinity binding parameters for influenza A virus were obtained by frontal elution method at optimized chromatographic conditions and immobilization schemes. The experimental data pointed out the possibility of selective isolation of hemeagglutinin from a mixture of vaccine proteins. The results obtained by fast affinity chromatography have shown functional and sterical correspondence viruslike synthetic models to influenza viruses. Additionally, the optimization of chromatographic conditions allowed isolation of influenza virus A while maintaining its virulence. The maximum value of adsorption capacity was registered for a monolithic disk, modified subsequently by chitosan and 2,6-sialyllactose and found to be equal to 6.9 x 10(12) virions/mL support.