New precursors for hexanitrohexaazaisowurtzitane (HNIW,CL‐20)

Two new polyacylhexaazaisowurtzitanes were synthesized. Pentaacetyl‐ or pentaacetylformylhexaazaisowurtzitane can be a precursor in the preparation of HNIW, recently developed highly energetic material.     

Synthesis and antihyperglycemic activity of erythrose,ribose and substituted pyrrolidine containing thiazolidinedione derivatives

A series of erythrose, ribose, and substituted pyrrolidine containing 2,4-thiazolidinediones were synthesized. Among them, thirteen unsaturated thiazolidinediones, six saturated thiazolidinediones and two unsaturated malonates were evaluated for their ability to enhance glucose utilization in cultured L6 myocytes. On the basis of the in vitro activity, 5-[4-[2-(1-benzyl-3,4-bis-benzyloxypyrrolidin-2-yl)ethoxy]benzylidene]thiazolidine-2,4-dione 24b was selected as the candidate for further pharmacological studies.     

Proteomic analysis of the cellular proteins induced by adaptive concentrations of hydrogen peroxide in human U937 cells

When cells are first exposed to low levels of oxidative stress, they develop a resistance to a subsequent challenge of the same stress, even at higher levels. Although some protein(s) induced by oxidative stress likely mediated this adaptive response, the nature of these proteins is unknown. In this study, the total proteins extracted from human U937 leukemia cells exposed to 50 micromM H(2)O(2) for 24 h to induce an optimal protective response were analyzed by two-dimensional polyacrylamide gel electrophoresis. H(2)O(2) treatment induced elevation of level of 34 protein spots. An analysis of these spots by a matrix associated laser desorption/ionization time-of-flight mass spectrometry identified 28 of the H(2)O(2)-induced proteins. These include proteins involved in energy metabolism, translation and RNA processing, chaperoning or mediating protein folding, cellular signaling, and redox regulation, as well as a mitochondrial channel component, and an actin-bundling protein. Therefore, it appears that the cellular adaptation to oxidative stress is a complex process, and is accompanied by a modulation of diverse cellular functions.     

Loss of trace impurities during NAA of liquid reagents

The loss of trace elements during NAA of five liquid reagents, hydrofluoric acid, hydrochloric acid, nitric acid, hydrogen peroxide and deioniyed water, has been investigated using 17 radioactive tracers of⁴⁶Sc,⁵¹Cr,⁵⁴Mn,⁵⁹Fe,⁶⁰Co,⁶⁴⁵Zn,⁷⁵Se,⁸⁵Sr,⁹⁵Zr,¹¹³Sn,¹²⁴Sb,¹⁵¹Eu,¹⁶⁰Yb,¹⁷⁷Lu,¹⁸²Ta,²³³Pa. Two kinds of container quartz and polyethylene have been used for irradiation and also for preconcentration of the reagents. The containers were cleaned before use by washing-leaching-rinsing procedure. The reagents were preconcentrated by subboiling evaporation under the infrared lamp in clean bench. The loss of trace elements has been revealed to be severer for the reagents of hydrochloric acid and nitric acid in the container of quartz than for the other cases, while that is lowest for hydrogen peroxide.     

Generating and Adding Flows on Locally Complete Metric Spaces

As a generalization of a vector field on a manifold, the notion of an arc field on a locally complete metric space was introduced in Bleecker and Calcaterra (J Math Anal Appl, 248: 645–677, 2000). In that paper, the authors proved an analogue of the Cauchy–Lipschitz Theorem, i.e they showed the existence and uniqueness of solution curves for a time independent arc field. In this paper, we extend the result to the time dependent case, namely we show the existence and uniqueness of solution curves for a time dependent arc field. We also introduce the notion of the sum of two time dependent arc fields and show existence and uniqueness of solution curves for this sum.     

Power flow model of flexural waves in finite orthotropic plates

In this paper, an approximate power flow model is developed for the analysis of the flexural waves in finite orthotropic plate transversely vibrating in the medium-to-high frequency ranges. The derived energy equation for the model is expressed with time- and locally space-averaged farfield wave energy density. It could be the more general form than that of the conventional power flow analysis model seen in the isotropic plate. With the derived model, dynamic characteristics varying with the direction can be expressed. To verify the validity and accuracy of the model, numerical analyses are performed for the case where a finite rectangular plate is excited by a harmonic point force, and the calculated results expressed with the energy levels are compared with classical modal solutions by changing the frequency and the damping loss factor of the plate. The dominant power transmission paths in the plate are also predicted from the distribution of the approximate intensity fields.