Zur Kenntnis der Strukturviskosität einiger Sole polymerer Kohlehydrate

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ChemInform Abstract: The Crystal Structures of m,o‐Ce3Pt4Sn6 and Ce1‐xPt6Al13+2x.

Single crystals of Ce₃Pt₄Sn₆ (I) and Ce_1‐xPt₆Al_13+2x (x = 0.207, (II)) are isolated by mechanical fragmentation of specimens grown from self‐fluxes (Sn or Al, resp.) by slow cooling from the melt.     

Axonal outgrowth is associated with increased ERK 1/2 activation but decreased caspase 3 linked cell death in Schwann cells after immediate nerve repair in rats

Background  

Extracellular-signal regulated kinase (ERK1/2) is activated by nerve damage and its activation precedes survival and proliferation of Schwann cells. In contrast, activation of caspase 3, a cysteine protease, is considered as a marker for apoptosis in Schwann cells. In the present study, axonal outgrowth, activation of ERK1/2 by phosphorylation (p-ERK 1/2) and immunoreactivity of cleaved caspase 3 were examined after immediate, delayed, or no repair of transected rat sciatic nerves.     

Pressure loading of detonation waves through 90-degree bend in high pressure H2–O2–N2 mixtures

Detonation experiments are conducted to investigate the detonation wave behavior in steam pipelines of boiling water reactors. Accumulated gases in BWRs are stoichiometric hydrogen/oxygen mixtures diluted with steam at 7 MPa. In the experiment, flammable gas mixture diluted with nitrogen at room temperature and up to 5 MPa is used to achieve equivalent detonation condition. Two test pieces are used, one is straight tube and the other is 90-degree bend. No initial pressure dependency in detonation wave behavior is observed in the experiments. However, in the straight tube tests, detonation velocities higher than theoretical values are measured when the initial pressures are greater than 2.3 MPa. This result is considered as attribution of real gas effect. In the 90-degree bend experiments, pressure time histories reveal pressure loads greater than the straight tube portion at two locations. One is a high pressure peak at the extrados of the bend and the other is a double pressure peak just downstream of the bend outlet. Second pressure peak just downstream of the bend outlet is due to transverse wave propagation. Additionally, the largest impulse is observed not at the extrados of the bend but at the intrados of bend outlet. These results show the importance of more investigations on transverse wave behaviors in failure potential evaluation.     

Study of the relationship between electrophoretic mobility of the diabetic red blood cell and hemoglobin A1c by using a mini-cell electrophoresis apparatus.

A mini-cell electrophoresis system using capillary tubing (50 microm inner diameter, length ca. 10 mm and volume ca. 20 nL) was applied to measure the electrophoretic mobility of red blood cells of 89 patients with diabetes on single cell level. A significant negative correlation was observed between hemoglobin A1c and the average electrophoretic mobility, with a correlation coefficient of 0.793. By statistically processing the electrophoretic mobility of each single red blood cell, it became clear that the reduction of the average value of electrophoretic mobility was caused by the reduction of the relative frequency of the red blood cell with high mobility. The cause of the average reduction was not the shift of electrophoretic mobility of all red blood cells to the lower mobility.     

Alkylative Carbocyclization of ω‐Iodoalkynyl Tosylates with Alkynyllithium Compounds Through a Carbenoid‐Chain Process Leading to (1‐Iodoprop‐2‐ynylidene)tetrahydrofurans and ‐cyclopropanes

Alkylative carbocyclization reactions of ω‐iodoalkynyl tosylates with alkynyllithium compounds to give products with incorporated iodine atoms are described. Slow addition of 2‐(3‐iodoprop‐2‐ynyloxy)ethyl tosylates to 1‐alkynyllithium compounds in tetrahydrofuran at 40 °C followed by additional stirring at this temperature gives (Z)‐3‐(1‐iodoprop‐2‐ynylidene)tetrahydrofurans stereoselectively in good to moderate yields. Under similar conditions at 0 °C, 4‐iodobut‐1‐ynyl tosylates react with 1‐alkynyllithium compounds to give (1‐iodoprop‐2‐ynylidene)cyclopropanes. The carbocyclization reactions are proposed to proceed through a new carbenoid‐chain process involving the exo cyclization of a lithium acetylide intermediate and the vinylic substitution of the resulting TsO,Li‐cycloalkylidenecarbenoids (Ts=tosyl) by 1‐alkynyllithium compounds.     

Formycin A resistant mutants due to defect in adenosine transport system in Vibrio parahaemolyticus

An antibiotic formycin A inhibited growth of Vibrio parahaemolyticus under certain conditions, which suggested that formycin A was taken up by cells under these conditions. We found that formycin A was transported via the adenosine transport system which we previously reported as a Na(+)-coupled cotransport system. We isolated many formycin A resistant mutants, and about half of them grew very poorly on adenosine as a sole source of carbon. Judging from their reversion frequencies, these mutants seemed to have single mutations. Respiration driven uptake of 14C-adenosine was not observed in such mutants; also, Na+ uptake induced by the addition of adenosine or formycin A to a cell suspension was completely abolished in them. Thus we conclude that these mutants possess a defect in the Na+/adenosine cotransport system, and have become formycin A resistant.     

Evidence for two energy scales in the superconducting state of optimally doped (Bi,Pb)2(Sr,La)2CuO6+delta

We use angle-resolved photoemission spectroscopy to investigate the energy gap(s) in (Bi,Pb)2(Sr,La)2CuO6+delta. We find that the spectral gap has two components in the superconducting state: a superconducting gap and pseudogap. Differences in their momentum and temperature dependence suggest that they represent two separate energy scales. Spectra near the node reveal a sharp peak with a small gap below T(c) that closes at T(c). Near the antinode, spectra are broad with a large energy gap of approximately 40 meV above and below T(c). The latter spectral shape and gap magnitude are almost constant across T(c), indicating that the pseudogap state coexists with the superconducting state below T(c), and it dominates spectra around the antinode. We speculate that the pseudogap state competes with the superconductivity by diminishing spectral weight in antinodal regions, where the superconducting gap is largest.     

Two Non-closure Properties on the Class of Subexponential Densities

Relations between subexponential densities and locally subexponential distributions are discussed. It is shown that the class of subexponential densities is neither closed under convolution roots nor closed under asymptotic equivalence. A remark is given on the closure under convolution roots for the class of convolution equivalent distributions.