Reactive and Highly Submicron Magnetic Latexes for Bionanotechnology Applications

Summary: Colloidal particles are largely used in biomedical applications as a solid support, as a carrier, as nanoreactors and as labels for target molecule detection. With the recent development of bionanotechnology, more appropriate colloidal particles should be elaborated. In this direction, new specification are listed in order to develop reactive nanoparticles to be use in microsystems, microfluids and all combined systems in which we can conduct sample preparation, specific capture, purification, concentration and detection in small volume (generally less than 100 µl). Then the aim of this short review is to give to the readers some recent orientations of reactive magnetic latex particles for in vitro bionanotechnology applications.     

Estimation of vertical wind velocity using doppler radar data with vorticity constraints

The vorticity equation and the mass continuity equation are used as constraints to aid in calculation of the vertical component of a wind field from horizontal wind components. Typically the horizontal wind components result from estimations obtained from radar data. Using a Hilbert space minimization formulation, we characterize the estimated vertical velocity as a solution of an elliptic boundary value problem whose coefficients are functions of the horizontal wind components. Differentiable dependence of the vertical component of the wind field with respect to the horizontal fields is established. Finite dimensional approximating problems are obtained. A numerical study is presented using a sample problem based on the Beltrami flow to compare accuracy of the estimated vertical wind component with the exact. Also, sensitivity to perturbations in horizontal wind components are observed.     

Piperidinium Hydrogen Sulfate (PHS) as an Efficient Ionic Liquid Catalyst for the Synthesis of Imidazole Derivative under Solvent‐Free Condition

Piperidinium hydrogen sulfate is used as a very important new catalyst for the synthesis of the biologically active compounds from a series of multi‐substituted imidazole components by the simple reaction of benzyl with different aromatic aldehydes, ammonium acetate, and phenethylamine or butylamine as amine derivatives. The key merits of this method are very shorter reaction times, excellent yield, and ease of stabilization. Furthermore, the produced products can be purified by a non‐chromatographic technique, and the catalyst is reusable. All of these new synthesized components have been characterized and checked from spectral data: IR, ¹H‐NMR, and ¹³C‐NMR spectra and elemental analyses.     

The Chemistry of Acetylpyrazoles and Its Utility in Heterocyclic Synthesis

A literature survey revealed that a great deal of interest has been focused on the synthesis of functionalized pyrazole derivatives due to their synthetic and biological potentialities. The pharmacological activities that have been found for some pyrazole derivatives include selective enzyme inhibition, antiviral, estrogen receptor agonist, anti‐inflammatory, anticancer, antiobesity, and antitumor properties. Other activities such as potential inhibitors of HIV‐1, pesticides, fungicides, and antihypertensive agents were reported for other pyrazole derivatives. This review summarizes the synthetic methods and reactions of 3‐acetyl‐pyrazoles, 4‐acetyl‐pyrazoles, and 3,4‐di‐acetyl‐pyrazoles. Most reaction types have been successfully applied and used in the production of biologically active compounds. The aim of this review is to focus mainly on the utility of acetylpyrazole derivatives in the synthesis of heterocyclic compounds during the period 1990–2018.     

Synthesis of Novel Bis(pyrido[2,1‐a]isoquinolines) Linked to Aliphatic or Aromatic Core via Ether Linkage

A synthesis of novel bis(pyrido[2,1‐a]isoquinoline‐1,3‐dicarbonitriles) by the multicomponent reaction of 2‐(6,7‐dimethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile with the corresponding bis(aldehydes) and malononitrile in the presence of basic catalysts was reported.     

Convenient synthesis of fused heterocycles from α-ketohydroximoyl chlorides and heterocyclic amines

Nitroso derivatives of imidazo[1,2-a]pyridine ( 11, 13, 14 ), imidazo[1,2-a]pyrimidine ( 15 ), imidazo[1,2-a]pyrazine ( 16 ), imidazo[1,2-b]pyrazole ( 17 ), and imidazo[1,2-b]-1,2,4-triazole ( 19 ) were obtained in good yields from α-ketohydroximoyl chlorides 3 and 2-aminopyridines ( 4–6 ), 2-aminopyrimidine ( 7 ), 2-aminopyrazine ( 8 ), 5-amino-3-phenylpyrazole ( 9 ), and 3-amino-2H-1,2,4-triazole ( 10 ), respectively. Under different conditions, the reaction of 3 with 3-amino-2H-1,2,4-triazole ( 10 ) and 2-aminopyrazine ( 8 ) afforded the noncyclized substitution products 18 and 22 , respectively. The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectral data, and alternate synthesis wherever possible.     

L-Poisson integral representations of solutions of the Hua system on the bounded symmetric domain SU(n,n)/S(U(n)×U(n))

Let positive definite} be the matrix ball of rank n and let H_D be the associated Hua operator. For a complex number λ, such that Reiλ>n−1 we give a necessary and sufficient condition on solutions F of the following Hua system of differential equations on D:

     

A computer method for simulating service loads

A recently presented study addressed the problem of analyzing field data that are best characterized as nonstationary stochastic signais. The analysis method hypothesizes that the nonstationary signal consists of two stationary signals, which belong to different populations, occurring consecutively according to a suitable probabilistic model. The analysis procedure involves the following: segmenting the time history, estimating the population of each segment, estimating the power spectrum of each segment, averaging the power spectra which belong to each population, presenting the power spectra via parameters of digital filters (which shape white noise sequences into sequences with the measured power spectra), and measuring the parameters of the probabilistic model. In this paper a simulation method is presented that uses the results of the analysis method mentioned above to create a sequence that simulates the statistical characteristics of the nonstationary field data. This simulation method is designed to be efficiently implemented on a general-purpose computer of any size, including micros. First, a review of the stochastic model is given. Then the steps of simulation are presented: generating a white sequence on the digital computer, generating the probabilistic model, and developing an algorithm for using digital filters in shaping the power spectra. Sample results are shown to reflect the soundness of the procedure. This simulation method can prove useful in computer studies of the fatigue of mechanical components under field loading. Since it is exactly reproducible in different laboratories, this method can also serve in comparison studies of fatigue-life prediction procedures. Paper was presented at V International Congress on Experimental Mechanics held in Montreal, Quebec, Canada on June 10–15, 1984.     

Crystal Structure,Dielectric Characteristics and Conduction Mechanism of a New Hybrid Material,Tetra(Phenylpiperazinium) Decachlorotriplumbate(II)

Monocrystalline (C₁₀H₁₅N₂)₄Pb₃Cl₁₀ was obtained via an aqueous solution reaction and characterized by single-crystal X-ray diffraction technique, elemental analyses, IR spectroscopy, UV–Vis spectrum, photoluminescence properties and thermal analysis. Structural characterization reveals that the title compound is built from [Pb₃Cl₁₀]^4? units sharing Cl2 atom to form 2-D [Pb₃Cl₁₀] _n ^4n? layers, these anions are linked to the organic cations via N–H···Cl and C–H···Cl hydrogen bonding. Moreover, dielectric relaxation spectroscopy has also been determined to show different molecular motions. Measurements of AC conductivity as a function of frequency at different temperatures indicated the hopping conduction mechanism.