Sequencing of antisense DNA analogues by capillary gel electrophoresis with laser-induced fluorescence detection

A method using capillary gel electrophoresis with laser-induced fluorescence detection is described which permits complete sequence determination of antisense DNA analogues of unknown sequence. This method, originally created as a tool to confirm the sequence of antisense oligonucleotides being developed as therapeutic drugs, utilizes data collected under a range of experimental conditions described by the Ogston model as applied to gel electrophoresis. A linear relationship independent of experimental conditions between the relative electrophoretic migration time and the oligonucleotide base number was observed and is shown to be consistent with a simplified version of this model and can be used to facilitate the sequence determination.     

Interaction between Ti-gel and silver, copper, as well as nickel compounds under ultrasound irradiation

Ag-TiO₂, Cu-TiO₂ and Ni-TiO₂ were prepared by sonication. The interactions of Ti-gel with silver, copper and nickel ions under ultrasound irradiation are very different, although these ions can be dispersed very well in titania. The results of EDXA and XRD analysis indicate that Ti-gel does not react with AgCl and crystallizes unaffectedly to form rutile. M(OH)₂ (M = Cu and Ni), on the other hand, favors polycondensation with Ti-gel and affects the crystallization of Ti-gel. CuO favors stabilization of the anatase phase. Ni²⁺ ions tend to incorporate more easily into titania than Cu²⁺ ions do when the samples are calcined. TEM, and BET were also used to characterize the samples.     

Copolymerization of styrene. V. Copolymerization with α-cyanocinnamamide

Copolymers of styrene with α-cyanocinnamamide were prepared by free radical initiation in bulk and in DMF solution and also by thermal initiation in bulk. The copolymerization parameters were determined by the conventional scheme of copolymerization and by an improved scheme taking into account the penultimate unit. Different values of the copolymerization parameters were obtained at the above mentioned different polymerization conditions, indicating the existence of a solvent effect. The influence of the comonomer on some of the basic properties, like intrinsic viscosity, solubility, melting range, and glass transition temperature and on some mechanical and behavior properties of the copolymers was studied in comparison with homopolystyrene.     

Controlling the agglomeration of anisotropic Ru nanoparticles by the microwave-polyol process

A rapid polyol process for the synthesis of ruthenium nanoparticles was developed using microwave irradiation. A colloidal solution of monodispersed anisotropic Ru metal nanoparticles (mean particle size 2-6 nm) with different aspect ratios was obtained first. Particles with different degrees of agglomeration have also been synthesized using monodisperse particles as seeds and PVP (poly-N-vinyl-2-pyrrolidone) as the stabilization reagent. The stabilization mechanisms of different protective reagents were studied by UV-vis spectra. The HRTEM images indicated that dendritic particles formed by controlling agglomeration consisted of single-crystal domains with a random crystalline orientation.     

Synthesis of alpha-MoTe2 nanorods via annealing Te-seeded amorphous MoTe2 particles

Semiconductor alpha-MoTe2 nanorods have been synthesized by annealing Te-seeded particles of an amorphous MoTe2 intermediate. This intermediate is prepared by a solution reaction between Mo(CO)6 and elemental Te in diphenylmethane. The as-synthesized products were characterized by structural, compositional, and morphological techniques of X-ray diffraction, selected area electron diffraction, selected area energy dispersive spectroscopy, energy dispersive X-ray analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The results of the annealing process are MoTe2 nanorods with diameters of 50-200 nm and lengths ranging from 0.1 to 3.0 microm. Here, the rodlike structure of MoTe2 is reported for the first time, and added to the list as one kind of new morphology of MoTe2 nanomaterials. A mechanism for the formation of the nanorods is proposed. The sandwich-layered structure of Te-Mo-Te and the similarity in the structure between hexagonal alpha-MoTe2 and hexagonal Te are responsible for the formation of nanorods of MoTe2.     

Coating noble metal nanocrystals (Ag, Au, Pd, and Pt) on polystyrene spheres via ultrasound irradiation

The method of ultrasound irradiation is used for anchoring metallic nanocrystals (Ag, Au, Pd, and Pt) onto the surface of polystyrene spheres. In former studies, almost all the sonochemically prepared, coated metallic nanomaterials were formed as amorphous nanoparticles (Pol, V. G.; et al. Langmuir 2002, 18, 3352; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1111; Zhong, Z. Y.; et al. Chem. Mater. 1999, 11 (9), 2350; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1378), which were coated on various substrates (silica spheres, carbon spherules, titania, and alumina). On the other hand, the noble metal nanoparticles deposited on polystyrene spheres via ultrasound irradiation yielded nanocrystalline Ag, Au, Pd, and Pt particles on the surface of polystyrene as as-synthesized materials. The sonochemical mechanism is proposed based on chemical interactions between the particles.     

Operators with resolvent of bounded characteristic

It is proved that if T is a bounded linear operator on a complex Banach space such that the sequence of norms {Tⁿ, n = 1,2, } is of power growth, then the resolvent of T is of bounded characteristic on the open unit disc D in the complex plane, if and only if T is annihilated by a nonzero holomorphic function on D with infinitely differentiable boundary values. This is analogous to the known result that an operator on a complex Banach space has rational resolvent, if and only if it is annihilated by a nonzero polynomial.     

A thermochemical analysis of inhalational anesthetics

The mechanism of the anesthetic process is of interest both to the clinician and to the pharmacologist. However, this is still an unsettled issue and a multitude of models have been proposed for the process. Noticing that most models propose either a molecular perturbation by the agents or an effect on some colligative property, we explore in this article the thermodynamical consequences of these postulations. Comparison of these with experimental findings is then made. The comparison shows the inconsistency of many of the models with the facts: (i) it refutes the long accepted conviction, culminated in the unitary hypothesis, that general anesthetics act not at a particular receptor site but invariably on all. Some consequences of this finding are demonstrated. (ii) it implies that a simple phospholipid medium is not feasible as an anesthetic site. (iii) it infers that proteins do have the properties required from anesthetic sites.Dedicated to Prof. Menachem Steinberg on the occasion of his 65th birthday     

Depositing nanoparticles inside millimeter-size hollow tubing

The inner and the outer walls of hollow tubing with an inner diameter of 0.4-0.9 cm and an outer diameter of 0.6-1.3 cm were coated with silver nanoparticles (NPs) by a one-step process using ultrasound irradiation. The structure and morphology of the nanoparticles (NPs) inside the hollow tubing and on the outer surface were characterized using methods such as XRD, TEM, HR-TEM, and HRSEM. The inner surface of the tubing was found to be coated with more silver than the outer surface. The coating was done on tubing made of rubber, PVC, Teflon and polyethylene. Sonochemistry is demonstrated as a method for depositing nanoparticles on the inner wall of a tube.