Experimental investigation of geologically produced antineutrinos with KamLAND

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.     

A novel,practical synthesis of 18-norsteroids

Zusammenfassung Eine einfache Synthese von 18-Nor-Pregnan-Derivaten durch die Decarboxylierung eines 12-Keto-18-Säure-Lactons (-20) wird beschrieben.     

Familial Parkinson disease gene product, parkin, is a ubiquitin-protein ligase

Autosomal recessive juvenile parkinsonism (AR-JP), one of the most common familial forms of Parkinson disease, is characterized by selective dopaminergic neural cell death and the absence of the Lewy body, a cytoplasmic inclusion body consisting of aggregates of abnormally accumulated proteins. We previously cloned PARK2, mutations of which cause AR-JP (ref. 2), but the function of the gene product, parkin, remains unknown. We report here that parkin is involved in protein degradation as a ubiquitin-protein ligase collaborating with the ubiquitin-conjugating enzyme UbcH7, and that mutant parkins from AR-JP patients show loss of the ubiquitin-protein ligase activity. Our findings indicate that accumulation of proteins that have yet to be identified causes a selective neural cell death without formation of Lewy bodies. Our findings should enhance the exploration of the molecular mechanisms of neurodegeneration in Parkinson disease as well as in other neurodegenerative diseases that are characterized by involvement of abnormal protein ubiquitination, including Alzheimer disease, other tauopathies, CAG triplet repeat disorders and amyotrophic lateral sclerosis.     

Modulation of C2 and C3 gene expression of human peripheral blood monocytes by interleukin 1 beta, interferon gamma, tumor necrosis factor alpha and lipopolysaccharide.

The effect of interleukin 1 beta (IL-1 beta), interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF alpha) and lipopolysaccharide (LPS) on the expression of the C2 and C3 genes in human adherent monocytes was studied. Stimulation of monocytes with IFN-gamma increased both C2 and C3 mRNA. IL-1 beta also increased C2 mRNA level, whereas C3 gene expression was not enhanced. TNF alpha failed to increase either C2 or C3 mRNA. LPS increased C2 mRNA, but suppressed C3 gene expression. These results suggest that C2 and C3 production by monocytes is regulated by IL-1 beta and IFN-gamma in the local tissues.     

Activation-independent binding of human memory T cells to adhesion molecule ELAM-1.

The induction of an ensemble of adhesion molecules on endothelial cells by inflammatory cytokines is likely to be crucial to the differential migration of T-lymphocyte subsets into inflammatory sites. Two molecular pathways involving the VLA-4 and LFA-1 integrins are known to mediate T-cell adhesion to activated endothelium. Here we show that a third pathway involving the rapidly inducible endothelial cell-surface adhesion molecule ELAM-1 contributes to the binding of resting CD4+ T cells to IL-1-induced human endothelial cells. All three pathways contribute to the greater adhesion to endothelium of memory T cells than naive T cells. There are two unique features of T-cell adhesion to purified ELAM-1: first, ELAM-1 exclusively mediates adhesion of memory T cells; second, memory T-cell binding to ELAM-1 is independent of acute activation events that regulate integrin-mediated adhesion. Thus, ELAM-1 may be of primary importance in the initial attachment of memory T cells to inflamed endothelium in vivo and to the preferential migration of memory T cells into tissue and inflammatory sites.     

二元置换固溶体点阵驻波的研究

将点阵浓度驻波与点阵位移驻波概念统一处理后提出了点阵驻波概念，利用点阵驻模型计算了二元置换固溶体产生的漫散射振幅与原子分布所形成的点阵波振幅的定量关系。结果表明：在倒易空间中任意一点的漫散射振幅正比于该点所代表的点阵驻波（包括点阵浓度驻波与点阵位移驻波与点阵位移驻波）的振幅，利用点阵波概念首次解释了实验发现的有序化与调幅分解共存的现象，而这两类反应长期以来被经典固溶体理论认为是互不相容或不可共存的     

Interaction between human evoked electrospinograms elicited by segmental and descending volleys

Summary Interaction between the slow negative-positive waves of human evoked electrospinograms produced by descending and segmental volleys was tested under general anaesthesia. A partial occlusion was demonstrated in these slow waves.This work was supported in part by the Japanese Ministry of Education.