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Autosomal short-tandem repeats (STRs) were typed in ethnic populations of Kubachians, Dargins, Avars, Lezgins, Kumiks, and Nogais of the Caucasus (Daghestan, Russia) at the University of Utah. Daghestan ethnic populations demonstrated differences in STR allele frequency distributions, but these differences were much lower among these ethnic groups compared to worldwide ethnic groups. The observed genetic diversity was low while F(ST) values were high, both of which provided supporting evidence for small population sizes and high levels of isolation among the ethnic groups. An analysis of genetic distance from the three major continents, encompassing Daghestan populations and groups, reveals three distinct clusters: all populations of African affiliation, European and Daghestan populations except the Nogais, and Asian populations with ethnic Nogais.  相似文献   
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Cross-correlation and autocorrelation histograms were constructed with the aim of studying correlated spike activity of neurons in the visual and sensorimotor regions of both hemispheres of the rabbit brain before and after stimulation of the right and left lateral hypothalamic regions, which generates food-motivated responses. Stimulation of the left hypothalamus produced larger rearrangements in correlated neuron firing than stimulation of the right hypothalamus. Stimulation of the left hypothalamus, unlike that of the right hypothalamus, was followed by significant increases in the numbers of pairs of left hemisphere neocortical neurons with linked activity, and also induced the sequential firing of neurons in a particular defined order: sensorimotor cortex cells fired first, followed by visual cortex neurons after delays of up to 120 msec. It is concluded that cortical interhemisphere asymmetry in conditions of hunger is associated with nonuniform functioning of the right and left lateral hypothalamic regions. Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow. Translated from Fiziologicheskii Zhurnal Vysshei Nervnoi Deyatel'nosti, Vol. 46, No. 6, pp. 1068–1075, November–December, 1996.  相似文献   
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Refocused insensitive nucleus enhancement by polarization transfer (RINEPT) from protons (1H) to a J-coupled phosphorus (31P) has been incorporated into three-dimensional (3D) chemical-shift-imaging (CSI) sequence on a clinical imager. The technique is demonstrated on a phantom and in in vivo human brain. The polarization-transfer efficiency (~1.2) is lower than the theoretical maximum of γ1H/γ31P≈ 2.4 resulting from 1H-1H homonuclear J couplings of similar magnitude competing with the 1H →31P transfer. Nevertheless, compared with direct 31P Ernst-angle excitation, signal gains of up to × 1.8 were obtained mainly as a result of T1 differences between 31P and the 1H. Spectral interpretation is simplified by editing out all non-proton-coupled 31P signals. The duration, ~50 min, and power deposition, ~1 W · kg?1, make the application suitable for human studies.  相似文献   
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Medical investigation was made of 271 workers including 112 males and 159 females exhibited to selenium concentrations lower MAC. The atom absorption spectrometry technique was applied to determine the selenium content levels in blood and urine. The analysis performed revealed increased contents of selenium in the blood of 20.1% and in the urine of 5.5% of those examined. The selenium excretion which followed the use of antidote increased twice. No relationship between the duration of exposition and blood and urine selenium content was revealed. Antidote therapy with CaNa2 EDTA was studied in 16 inpatient clinical cases.  相似文献   
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The co-segregation in one pedigree of bipolar affective disorder with Darier's disease whose gene is on chromosome 12q23-q24.1, and findings from linkage and association studies with the neighbouring gene of phospholipase A2 (PLA2) indicate that PLA2 may be considered as a candidate gene for affective disorders. All relevant genetic association studies, however, were conducted on bipolar patients. In the present study, the possible association between the PLA2 gene and unipolar affective disorder was examined on 321 unipolar patients and 604 controls (all personally interviewed), recruited from six countries (Belgium, Bulgaria, Croatia, Germany, Greece, and Italy) participating in the European Collaborative Project on Affective Disorders. After controlling for population group and gender, one of the eight alleles of the investigated marker (allele 7) was found to be more frequent among unipolar patients with more than three major depressive episodes than among controls (P<0.01); genotypic association was also observed, under the dominant model of genetic transmission (P<0.02). In addition, presence of allele 7 was correlated with a higher frequency of depressive episodes (P<0.02). These findings suggest that structural variations at the PLA2 gene or the chromosomal region around it may confer susceptibility for unipolar affective disorder.  相似文献   
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