Synthesis and characterization of near IR fluorescent albumin nanoparticles for optical detection of colon cancer

Near IR (NIR) fluorescent human serum albumin (HSA) nanoparticles hold great promise as contrast agents for tumor diagnosis. HSA nanoparticles are considered to be biocompatible, non-toxic and non-immunogenic. In addition, NIR fluorescence properties of these nanoparticles are important for in vivo tumor diagnostics, with low autofluorescence and relatively deep penetration of NIR irradiation due to low absorption of biomatrices. The present study describes the synthesis of new NIR fluorescent HSA nanoparticles, by entrapment of a NIR fluorescent dye within the HSA nanoparticles, which also significantly increases the photostability of the dye. Tumor-targeting ligands such as peanut agglutinin (PNA) and anti-carcinoembryonic antigen antibodies (anti-CEA) were covalently conjugated to the NIR fluorescent albumin nanoparticles, increasing the potential fluorescent signal in tumors with upregulated corresponding receptors. Specific colon tumor detection by the NIR fluorescent HSA nanoparticles was demonstrated in a chicken embryo model and a rat model. In future work we also plan to encapsulate cancer drugs such as doxorubicin within the NIR fluorescent HSA nanoparticles for both colon cancer imaging and therapy.     

The Nanostructures Produced by Laser Ablation of Metals in Superfluid Helium

The coagulation of impurities in superfluid helium, in contrast to that in all other liquids where spherical colloid particles are usually produced, led to producing thin and long nanowires with regular internal structure. This is due to the presence in HeII of quasi one-dimensional quantized vortices serving as condensation nuclei and providing a catalyzing effect on the process of any impurities coagulation. The metal was introduced into superfluid helium by laser ablation of targets made of gold, copper, nickel, permalloy, indium, lead, tin and bismuth immersed in liquid HeII. For all of these metals, the formation of thin (about 8 nm in diameter), long high-quality nanowires was observed after laser ablation. The structure of nanowires as well as of micron-sized metallic spheres, appeared as products at high laser pulse energy, providing evidence that they were formed via molten state. The spheres are metastable, and under damage of their surface, thousands of nanoballs emerge from their interior. The hollow shells left after this event are similar to those found as the products of laser ablation in normal fluids. The metal ablation into HeII bulk from thin film was found much less effective then that from thick foils.     

Crossover from Localized Spins to Weak Coupling Charge Carriers: Theory for Nuclear Spin-Lattice Relaxation in Copper Oxide HTSC

The dynamic spin susceptibility $\chi^{+,-}_{\mathrm{total}}(\omega,{\bf q})$ that takes into account the interplay of localized and itinerant charge carriers exhibits a diffusive-like, extremely narrow and sharp symmetric ring of maxima at very small wave vectors: $|{\bf q}|=q_{0}$ where q ₀∝ω/J≈10^?6 with the Nuclear Magnetic Resonance (NMR) frequency ω and the superexchange coupling constant J together with the peak at the antiferromagnetic wave vector Q=(π,π). The calculated plane copper ⁶³(1/T ₁) and oxygen ¹⁷(1/T ₁) nuclear spin-lattice relaxation rates from carrier-free right up to optimally doped La_2?x Sr _x CuO₄ are in good agreement with experimental data.     

A surname-based patent-related indicator: the contribution of Jewish inventors to US patents

It was found that the surname-based representation of Jewish authors in the top US biomedical journals corresponds to the representation of Jewish Nobel Laureates in Medicine among US laureates: Both of them are almost equally disproportionately high, with the ratio of actual to expected number close to 20 (Kissin, Scientometrics 89:273–280, 2011). The main aim of this study was to determine whether the contribution of Jewish inventors is also disproportionately high. The number of patents (US Patent and Trademark Office database) per thousand persons with the same surname (2000 Census) was determined (index P). Index P was compared with index A, which represents the number of the articles in the top US biomedical journals, and index G, which is based on the representation of a surname in the Google’s option “Discussions”, reflecting a combination of various business and leisure activities (designed as a negative control). The collective contributions of the 96 Jewish surname groups for each of the above indices were calculated. The ratio of actual to expected number of US patents was found to be disproportionately high—6.1 (p < 0.0001). At the same time, this disproportionality was four-fold lower than that related to biomedical articles (ratio of 6.1 vs. 23.3, p < 0.0001). There was some degree of correlation between index P and index A (r = 0.407, p < 0.0001), but no significant correlation was found between index P and index G. The role of various factors in the observed disproportionalities is discussed. The greater degree of disproportionality with biomedical research articles might be a consequence of traditional Jewish inclination towards occupations in medicine.     

Implementation of intra-cavity beam shaping technique to enhance pump efficiency

In this work we propose an implementation of a new intra-cavity beam shaping technique to vary the intensity distribution of the fundamental mode in a resonator cavity while maintaining a constant intensity distribution at the output. This method can be useful for fitting a transversal intensity profile of the required mode with a pump beam profile in the region of the active medium to increase mode discrimination.     

Increased significance of food wastes: Selective recovery of added-value compounds

A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources.     

Pluronic Block Copolymers Inhibit Low Density Lipoprotein Self-Association

Little is known about exogenous inhibitors of low-density lipoprotein (LDL) aggregation. The search for nontoxic and bioavailable inhibitors of LDL aggregation is of interest, especially considering that the suppression of the aggregation of LDL might represent a therapeutic approach. We hypothesized that amphiphilic copolymers of propylene oxide and ethylene oxide, the so-called Pluronic block copolymers, can be used to influence the aggregation of LDL. In this work we used Pluronic^® P85, L61 and F68. A comparative study of the effects of Pluronic block copolymers with various hydrophilic–lipophilic properties on the aggregation process of LDL showed that Pluronic copolymers with strong hydrophobic properties (P85 and L61) at concentrations close to or greater than the respective critical concentration of micelle formation inhibited the aggregation process of LDL; however, the “hydrophilic” Pluronic F68 had no effect on the aggregation of LDL at any concentration. Thus, the study demonstrated for the first time that Pluronic^® block copolymers inhibit LDL self-association. The possibility of modulating the aggregation of LDL by various Pluronic copolymers can be regarded as a prerequisite in the creation of new types of anti-atherosclerotic drugs.     

Characterization of porosity and defect imaging in ceramic tile using ultrasonic inspections

In this study, three different ultrasonic nondestructive methods (NDT) used to characterize porosity and identify defects in ceramic materials were employed as alternative approaches to conventional systems. A contact ultrasound technique, based on the A-scan, and measurements of the material frequency response were found to be useful for the characterization of porosity in porcelain tiles. Ceramic specimens with two types of simulated defects (a piece of paper and aluminum foil) were prepared and studied. The defects were readily identified in the ultrasonic A-scan and the location depth was measured. The technique, based on air-coupled ultrasound, was shown to be applicable for non-contact detection and imaging of defects in ceramic tiles.     

On the Poisson ratio and XRD determination of strain in thin films of Ce0.8Gd0.2O1.9

XRD measurement of the room temperature in-plane and out-of-plane d-spacings of the (422) diffraction peak of 11 thin film samples of fluorite Ce_0.8Gd_0.2O_1.9 demonstrates that the zz and xx (=yy) components of the strain tensor for this material are not related via a constant, i.e. the Poisson ratio, as is the case for elastic materials. Rather, these strains are independent. We attribute this behavior to the inelastic character of Ce_0.8Gd_0.2O_1.9 deriving from the chemical strain effect, i.e. the lability of point defect-containing complexes under stress. Chemical strain is dependent on the thermal and mechanical history of the film, and above 200 °C, is no longer observed, being transformed into elastic strain and stress. This transformation may compromise the mechanical stability of Ce_0.8Gd_0.2O_1.9 containing devices, which must operate over a broad temperature range. Measurements analogous to those described here can assist in predicting the magnitude of such an effect.