Multiple functions of microfluidic platforms: Characterization and applications in tissue engineering and diagnosis of cancer

Microfluidic system, or lab-on-a-chip, has grown explosively. This system has been used in research for the first time and then entered in the clinical section. Due to economic reasons, this technique has been used for screening of laboratory and clinical indices. The microfluidic system solves some difficulties accompanied by clinical and biological applications. In this review, the interpretation and analysis of some recent developments in microfluidic systems in biomedical applications with more emphasis on tissue engineering and cancer will be discussed. Moreover, we try to discuss the features and functions of microfluidic systems.     

Hyperfine structure studies of Tantalum

A narrow bandwidth ring dye laser pumped by an argon ion laser has been used to investigate the hyperfine structure of the even and odd parity levels of tantalum by optogalvanic spectroscopy in the wavelength range 5640 to 6050 Å. Seventeen transitions have been observed and eight of these have not been reported in the literature so far. These transitions involve 27 levels with 15 odd and 12 even parity configurations. The magnetic dipole hyperfine interaction constants A and the electric quadrupole interaction constants B for these levels have been computed and compared with the data available in literature. The results for the levels at 34799.71 cm^?1, 26960.46 cm^?1 and 19657.78 cm^?1 are reported for the first time.     

Luminescence characteristics of minerals separated from irradiated onions during storage under different light conditions

The aim of this study was to determine the effects of light conditions during 2 years of storage on the luminescence characteristics of contaminating minerals, isolated from irradiated onions of 2 different origins. The potential use of photostimulated luminescence (PSL) as a screening and thermoluminescence (TL) as a confirmatory identification method was investigated during post-irradiation periods. Nonirradiated onions had 1,612 photon counts (PCs), However, the irradiated onions had much higher PCs (45,672–469,696, positive). The PCs of the irradiated onions decreased with storage time. However, all the irradiated onions had PCs with positive values (>5,000) even after 2 years of storage except onions stored under natural light. The decline in PCs because of light conditions during storage was in the order of sunlight, artificial light, and a darkroom, respectively. Minerals extracted from the nonirradiated samples exhibited TL glow curves of low intensities with maximum peak after 300 ^°C. However, all irradiated samples had TL glow peaks in the temperature ranges of 185–225 ^°C. The TL intensity and TL ratio of the irradiated samples decreased during storage with a slight shift in the TL peak temperature towards higher temperatures. The TL characteristics were most promising for samples stored under natural light conditions, however all the irradiated onions could be identified even after 2 years of storage.     

Manganese porphyrins/mesoporous amberlyst 15 nanocomposites: Robust biomimetic catalysts for aqueous oxidation of olefins

In this study, the manganese complexes of N-methylated meso-tetra(2-, 3-, or 4 pyridyl)porphyrins, immobilized into the pores of the sodium salt of mesoporous amberlyst 15 nanoparticles (nanoAmbSO₃Na), nanoAmbSO₃@MnT(2-MePy)P (OAc), nanoAmbSO₃@MnT(3-MePy)P (OAc), and nanoAmbSO₃@MnT(4-MePy)P (OAc), were synthesized and characterized by field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), nitrogen adsorption/desorption porosimetry analysis, and diffuse reflectance UV–vis spectroscopy. FESEM images revealed a particle size less than ~40 nm for the nanocomposites. The results of BET are in accord with the occupation of the larger pores of the polymer matrix in the case of MnT(2-MePy)P (OAc) as the most sterically demanding metalloporphyrin of the series, and the smaller pores in the case of the other ones. The immobilized manganese porphyrins were used as catalysts for the oxidation of olefins with sodium periodate in the presence of imidazole (ImH) as the co-catalyst. The negligible oxidative destructions of the immobilized manganese porphyrins under the oxidative conditions allowed the comparison of the inherent catalytic activity of the metalloporphyrins, decreased as nanoAmbSO₃@MnT(4-MePy)P (OAc) > nanoAmbSO₃@MnT(3-MePy)P (OAc) ≫ nanoAmbSO₃@MnT(2-MePy)P (OAc). Contrary to the general belief that electron-deficient metalloporphyrins are more efficient catalysts than the electron-rich ones, the most electron-deficient metalloporphyrin of the series, that is, nanoAmbSO₃@MnT(2-MePy)P (OAc), showed the lowest catalytic activity. Due to the high oxidative stability of the immobilized manganese porphyrins, ring opening of epoxide competes with the epoxidation reaction to decrease the yield of epoxide at longer reaction times than the optimized one.     

Synthesis and characterization of optically active poly(amide-imide)s based on [N,N′-(4,4′-carbonyldiphtaloyl)-bis-lamino diacid]s and 1,5-bis(4-aminophenyl)penta-1,4-dien-3-one

Six dicarboxylic acids 3a-3f were synthesized by the reaction of 3,3’,4,4’-benzophenonetetracarboxylic dianhydride 1 with L-aminoacids 2a-2f in a solution of glacial acetic acid/pyridine(Py) at refluxing temperature.Then six new poly(amide-imide)s PAIs were synthesized from the direct polycondensation reaction of[N,N’-(4,4’- carbonyldiphtaloyl)-bis-L-amino diacid]s with 1,5-bis(4-aminophenyl)penta-1,4-dien-3-one(APPD).The polymerization reactions produced a series of new optically active PAIs with high yield and good inherent viscosity.Also these PAIs are optically active and soluble in various organic solvents.These resulting new polymers can be used in column chromatography for the separation of enantiomeric mixtures.The resulted polymers were fully characterized by means of FTIR and ~1H-NMR spectroscopy,elemental analyses,inherent viscosity measurements,solubility tests and thermogravimetric analysis(TGA).     

Observation on Symmetry Properties of Sodium Zinc(II)-2,9,16,23-phthalocyanine Tetracarboxylate in Water:NaOH Solution

The shift of the Q-band of sodium zinc(II)-2,9,16,23-phthalocyanine tetracarboxylate (ZnPc(COONa)₄) to about 800 nm is attributed to the influence of the electron-donating property of the carboxylate groups substituted in the β–position. ZnPc(COONa)₄ which was found to have a symmetry of D _2h characterized by a splitting of the Q transition. This splitting was interpreted by the formation of dianionic symmetric ZnPc(COONa)₄ resulting from the dissociation of the pyrrole protons as well as the possibility of Na⁺ dissolution of ZnPc(COONa)₄ in the aqueous solution of NaOH.     

Synthesis,anti‐migration and burning rate catalytic mechanism of ferrocene‐based compounds

One of the most important components of solid rocket propellant is the burning rate catalysts (BRC) which enhance burning rate of solid composite propellant. Low‐pressure exponents and stable burning rate are the key features of an excellent solid propellant. Addition of BRC to the propellant results in the increase of burning rate of the propellant and decrease in pressure exponents. Among all BRC, ferrocene‐based BRC have attracted much attention because of their better microscopic homogeneities in distribution, ignitability of the propellants and good compatibility with organic binder. However, the main barrier for the development and practical applications of ferrocene‐based BRC is their migration property. This article reviews the field and highlights recent progress. Copyright © 2014 John Wiley & Sons, Ltd.     

Silica Sulfuric Acid: A Versatile and Reusable Catalyst for Synthesis of Coumarin-3-carboxylic Acids in a Solventless System

Synthesis of substituted coumarin-3-carboxylic acid via Knoevenagel condensation of meldrum's acid with ortho-hydroxyaryl aldehydes in solventless system is described.     

Recurrence Tracking Microscope Based on Two Magnetic Mirrors

We introduce a recurrence tracing microscope based on the reflection of cold atoms from two magnetic mirrors placed in parallel. A cantilever is attached perpendicularly to one of the two mirrors at the lower end that probes surface structures. The quantum dynamics in the system provides the matter waves to store information on the height and spacing between the nanostructures. We use the recurrence tracking microscope in static and dynamic modes to study arbitrary and periodic nanostructures.