The presence of the nucleic acid of the spotted fever group (SPG) and typhus group (TG) rickettsiae was investigated in 200 serum specimens seropositive for SFG rickettsiae by multiplex-nested ...polymerase chain reaction with primers derived from the rickettsial outer membrane protein B gene. The DNA of SFG, TG, or both rickettsiae was amplified in the 24 serum specimens, and sequence analysis showed Rickettsia conorii, R. japonica, and R. felis in the specimens. R. conorii and R. typhi were found in 7 serum specimens, which indicated the possibility of dual infection in these patients. These findings suggest that several kinds of rickettsial diseases, including boutonneuse fever, rickettsialpox, R. felis infection, and Japanese spotted fever, as well as scrub typhus and murine typhus, are occurring in Korea.
This article assesses current understanding of hysteresis in transport relations, and its impact on the field. The rapid changes of fluxes compared to slow changes of plasma parameters are overviewed ...for both core and edge plasmas. The modulation ECH experiment is explained, in which the heating power cycles on-and-off periodically, revealing hysteresis and fast changes in the gradient-flux relation. The key finding is that hystereses were observed simultaneously in both the the gradient-flux and gradient-fluctuation relations. Hysteresis with rapid timescale exists in the channels of energy, electron and impurity densities, and plausibly in momentum. Advanced methods of data analysis are explained. Transport hysteresis can be studied by observing the higher harmonics of temperature perturbation δTm in heating modulation experiments. The hysteresis introduces the term δTm, which depends on the harmonic number m in an algebraic manner (not exponential decay). Next, the causes of hysteresis and its fast timescale are discussed. The nonlocal-in-space coupling works here, but does not suffice. One mechanism for 'the heating heats turbulence' is that the external source S in phase space for heating has its fluctuation in turbulent plasma. This coupling can induce the direct input of heating power into fluctuations. The height of the jump in transport hysteresis is smaller for heavier hydrogen isotopes, and could be one of the origins of isotope effects on confinement. Finally, the impacts of transport hysteresis on the control system are assessed. Control systems must be designed so as to protect the system from sudden plasma loss.
New amphiphilic block copolymers based on oligomeric polyethylenimine and poly(
d,
l-lactide-co-glycolide) (PEI–PLGA) were synthesized by directly coupling PLGA with a carboxyl terminal group to PEI. ...The block copolymers were prepared by varying the length of the hydrophobic PLGA block (
M
n
=6, 10, and 21
K), while that of the hydrophilic PEI block (
M
n
=423) was fixed. PEI–PLGA block copolymers were found to be self-assembled in water by using a PLGA segment as a hydrophobic aggregate block and a PEI segment as a hydrophilic corona-forming block. The block copolymers formed micelle-like aggregates with critical association concentration (cac) in the range of 1.54–2.57×10
−3
g/l in water. It was found that the size and cac of the aggregates depended on the hydrophobic block length and the ionic state of the PEI block. The aggregate size decreased and the cac increased, when the PLGA block length decreased and the PEI block was protonated. As a general program aimed at the development of a new nanoscopic drug carrier, the cellular uptake behavior of PEI–PLGA aggregates was compared with that of plain PLGA nanoparticles by using confocal microscopy. The results showed that PEI–PLGA aggregates was readily adsorbed onto the cell surfaces and translocated into the cytoplasm, implying their versatile applicability as a drug carrier.
A gene (ORF PH1035), annotated to encode an uncharacterized hypothetical protein in
Pyrococcus horikoshii, was first cloned and expressed in
Escherichia coli. The recombinant enzyme was purified to ...homogeneity by Ni–NTA affinity chromatography and its molecular mass was determined to be 49,871
Da by MALDI-TOF mass spectrometry. When the purified enzyme was reacted with nucleoside diphosphate–glucoses including UDP–glucose as a donor and glucose, rather than glucose-6-phosphate, as an acceptor, it specifically created a free trehalose. The enzyme was also able to partly hydrolyze the trehalose to glucose. The optimum pH was 5.5 and the enzyme was highly stable from pH 6 to 8. The deduced amino acid sequence showed a high homology with that of the glycosyl transferase group 1 (Pfam00534) in the BLAST search. The results suggest that the enzyme is a novel glycosyltransferase catalyzing the synthesis of the trehalose in the archaeon.
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