Pulmonary edema in mice infected withPlasmodium berghei. Involvement of catecholamines

Summary Mice inoculated withPlasmodium berghei developed a drastic and significant pulmonary edema. Treatment of animals with phenoxybenzamine rendered mice hyporeactive to this physiopathological alteration.This work was supported by a grant aided by «Conselho Nacional de Desenvolvimento Científico e Tecnológico» (CNPq, Brasil). Presented in preliminary form at the XIX Annual Meeting of the Brazilian Society of Tropical Medicine, Rio de Janeiro, R. J., February 20, 1983.Acknowledgments. We thank Mr Antonio Fernando de P. Oliveira and Solano S. Martins for their excellent technical help.     

Microtubule associated protein tau binds to double-stranded but not single-stranded DNA

Tau, a major microtubule-associated protein of the neuron, which is known to promote the assembly of and to stabilize microtubules, has also been seen associated with chromatin in neuronal cell lines, but its role in this subcellular compartment is still unknown. In this study, the binding of tau to DNA was investigated using the electrophoretic mobility shift assay. Using polynucleotide as probe, we found that tau bound to double-stranded but not to single-stranded DNA. Formation of tau-polynucleotide complex was disrupted by alkaline pH and a high concentration of NaCl, but was not affected by dithiothreitol. Electron microscopy revealed that the protein associated with the nucleic acid in a necklacelike manner. DNA-cellulose chromatography and radioimmunodot-blot analyses showed that calf thymus histones VI-S, VII-S and VIII-S could replace both recombinant human brain tau₃₅₂ (tau-23) and tau₄₄₁ (tau-40) from DNA. Thus, tau appears to bind to DNA reversibly in the presence of histones. Received 24 November 2002; received after revision 28 December 2002; accepted 30 December 2002 RID="*" ID="*"Corresponding author.     

A human homolog of the yeast gene encoding tRNA 2′-phosphotransferase: cloning,characterization and complementation analysis

The Saccharomyces cerevisiae TPT1 gene plays a role in removing the 2-phosphate from ligated tRNA during the maturation of pre-tRNA. Here we reported the cloning and characterization of the human TRPT1 gene as a homolog of yeast TPT1. The TRPT1 gene is located at human chromosome 11q13 and encodes a polypeptide of 253 amino acids. BLAST searches with its amino acid sequence revealed the ubiquitous occurrence of TRPT1 homologs and their functional relationships with the presence of the DUF60/KptA domain. Northern analysis demonstrated that the gene is primarily expressed in heart and skeletal muscle, with lower or undetectable levels in other tissues studied. A plasmid-shuffling experiment showed that the human TRPT1 gene could complement the tpt1 mutation in S. cerevisiaeReceived 19 March 2003; received after revision 25 April 2003; accepted 22 May 2003     

Coherence incoherence and dimensional crossover in layered strongly correlated metals

The properties of an interacting electron system depend on the electron correlations and the effective dimensionality. For example, Coulomb repulsion between electrons may inhibit, or completely block, conduction by intersite electron hopping, thereby determining whether a material is a metal or an insulator. Furthermore, correlation effects increase as the number of effective dimensions decreases; in three-dimensional systems, the low-energy electronic states behave as quasiparticles, whereas in one-dimensional systems, even weak interactions break the quasiparticles into collective excitations. Dimensionality is particularly important for exotic low-dimensional materials where one- or two-dimensional building blocks are loosely connected into a three-dimensional whole. Here we examine two such layered metallic systems with angle-resolved photoemission spectroscopy and electronic transport measurements, and we find a crossover in the number of effective dimensions from two to three with decreasing temperature. This is apparent from the observation that, in the direction perpendicular to the layers, the materials have an insulating character at high temperatures but become metal-like at low temperatures, whereas transport within the layers remains metallic over the whole temperature range. We propose that this change in effective dimensionality correlates with the presence of coherent quasiparticles within the layers.     

Continuous lobe reconnection in the mid-tail and its relationship to substorms： Cluster observations of continuous lobe reconnection in the mid-magneto tail

When the IMF turns southward, a great amount of magnetic energy is stored in the magnetotail, and the electric field across the magnetotail substantially enhances. As long as magnetic reconnection （MR） in the magnetotail initiates and continues, the magnetic field and plasma in the central plasma sheet are carried away to the near-Earth and down to the tail, the magnetic field and plasma in the lobe region enter the CPS and are involved in MR. We call this process “Continuous Lobe Reconnection （CLR）”. In this paper a detailed analysis of Cluster observation of MR through 2001--2003 is made. Plenty of CLR events are found that led to considerable changes of tail configuration, appearance of BBF, as well as large-scale bubbles in which both plasma temperature and number density substantially decrease. It is shown that in general CLR events last for dozens of minutes and have good correspondence to substorm initiation under the condition of continuous southward IMF.     

外耦合布拉格光栅5μm量子级联激光器

窄带宽的A1GaAs／GaAs布拉格光栅耦合到InP的半导体量子级联激光器从而产生稳定的激光频谱，其激光谱线宽度在1纳米左右。如果不加光栅，非稳定的自由激射的激光器的谱线宽度有30nm左右。隔离的分布式布拉格光栅可以独立调谐几个纳米。     

甲醛污染的危害及控制措施

针对修建和装饰材料中含有大量甲醛，对空气造成污染的现状，阐述了甲醛对人体的危害及甲醛产生的途径，提出了控制甲醛污染的一些措施。