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71.
C. Nicolau H. -D. Klenk K. Hildenbrand B. Reimann Alice Reimann H. Bauer 《European biophysics journal : EBJ》1979,5(1):11-23
The fluorescence depolarization of 1,6-diphenyl-hexatriene was used to study the dynamic properties of the hydrophobic regions of the lipid envelopes of ortho- and paramyxoviruses as well as of the Rous sarcoma virus and of the membrane lipids of susceptible and nonsusceptible cells.The systems investigated where active and inactive influenza viruses, and NDV virus acting on chick embryo fibroblasts and Rous sarcoma virus acting on susceptible (C/E) and nonsusceptible (C/B) chicken-cell.Polarization degrees and mean rotational correlation times of DPH embedded in viral lipids were significantly higher than those of DPH in the cell membranes, due to a higher rigidity of the virus envelopes. When suspensions of labelled viruses and unlabelled cells or unlabelled viruses and labelled cells were mixed, a characteristic change of the fluorescence polarization degrees with time was observed. This behaviour was ascribed to a label transfer from virus to cell membranes or vice versa.While the rate constants of label transfer from virus to cells and cells to virus were about the same for the penetrating viruses the rate constants of label release from inactive virus to cells were much larger than for the migration in the opposite direction. 相似文献
72.
A new virus, Mycoplasmatales virus-modicum 1 (MV-M1), was recovered from spontaneous plaques in lawns ofAcholeplasma modicum. Strain “mod” produced plaques onA. modicum strains but not on strains ofAcholeplasma laidlawii. Only MV-L3 of the three knownA. laidlawii viruses (MV-L1, MV-L2, and MV-L3) produced plaques onA. modicum. The MV-M1 virus was serologically distinct from the threeA. laidlawii viruses; filterable at 0.1 μm; partially sensitive to heat and Nonidet P-40; and chloroform labile. Spherical particles ranging
from 105 to 160 nm were observed in electron micrographs of negatively stained preparations. 相似文献
73.
Ming-liang Lee Demetra Rose Alice Lazzarini B. R. Rajendra L. J. Sciorra 《Human genetics》1979,51(3):343-347
Summary Monosomy 21, whether homogeneous or as a mosaicism, is very uncommon. We report here a 3-month-old white female with a low degree of monosomy 21 in the blood karyotype (6.5%, 110 cells counted) but not in the skin fibroblasts, which contained only the normal chromosome complement.The patient's physical features included microcephaly with frontal slanting; prominent occiput; ridge-shaped sutures; agenesis of the corpus callosum; large, prominent ears; high and narrow palate; micrognathia; tetralogy of Fallot; crowded toes; and dry, thick skin with very little subcutaneous tissue. The case is discussed in light of the suggested clinical features of the monosomy 21 syndrome and the possible implications of such a low-grade mosaicism in prenatal diagnosis. 相似文献
74.
Alice O. Martin L. Miller J. L. Simpson C. Thomas M. S. Rzeszotarski S. Elias Gloria E. Sarto V. A. Patel 《Human genetics》1979,48(2):211-219
Summary A variant chromosome no. 21 consisting of two stalks and two satellites in tandem was detected during a survey of a human isolate. The variant segregated in three generations of a large kindred. One male had the variant no. 21, a metacentric Y, and a 47, XXY complement; however, no other evidence of chromosomal nondisjunction was found. Computer-aided analysis of sequentially stained variant no. 21 chromosomes indicated that silver-stained material corresponded to the proximal stalk region (as defined defined by Giemsa). These data support the hypothesis that human nucleolar organizers are localized to the stalks of acrocentric chromosomes. 相似文献
75.
H. Karppanen Anna-Leena Sirn Alice Eskeli-Kaivosoja 《Prostaglandins & other lipid mediators》1979,17(3):385-394
Administration of PGF2α (0.2–6.4 μg) into the lateral cerebral ventricle (i.c.v.) induced dosedependent increases in blood pressure, heart rate and body temperature in urethane-anaesthetised rats, but had no effect on these parameters when the same dose range was administered intravenously. Peripheral pretreatment with sodium meclofenamate (50 mg/kg s.c.) shifted all the dose-response curves for PGF2α (i.c.v.) to the left, but indomethacin (50 mg/kg s.c.) did not significantly affect those changes. Central pretreatment with sodium meclofenamate or indomethacin (1.25 mg per rat i.c.v.) failed to modify significantly the effects of centrally administered PGF2α.The results support previous suggestions that PGF2α may participate in the central control of the cardiovascular and thermoregulatory systems, and also suggest that there may be differences in the sites and/or modes of action between sodium meclofenamate and indomethacin. 相似文献
76.
Steen Pedersen Solveig V. Reeh Jack Parker Robert J. Watson James D. Friesen Niels P. Fiil 《Molecular & general genetics : MGG》1976,144(3):339-343
Summary The presence of EF-Tu, RNA polymerase subunit , and EF-G on the dfus-3 genome and EF-Tu, ribosomal proteins L7/L12, and RNA polymerase subunit on the drif
d
18 genome has been confirmed using a two-dimensional gel electrophoresis technique sensitive to changes in isoelectric point and molecular weight. In this system two EF-Tu gene products could not be resolved. Following infection of ultraviolet light-irradiated Escherichia coli with either dfus-3 or drif
d
18, the EF-Tu gene, tufA, near 65 minutes on the genetic map is expressed as 3–4 copies per EF-G molecule. The EF-Tu gene, tufB, near 79 minutes on the genetic map, is expressed at about one-third of this rate. is expressed as 1 copy per EF-G molecule, as 0.14 per EF-G molecule and L7/L12 as 2.5 per EF-G. These figures compare well with the relative amounts found in exponentially-growing cells, in which the ratio of EF-Tu to EF-G is approximately 5. Almost 90% of the total number of proteins (calculated on a molecular weight basis) which theoretically can be encoded on the drif
d
18 have been identified on the two-dimensional gel. 相似文献
77.
78.
Cristiano Carlomagno Monia Cabinio Silvia Picciolini Alice Gualerzi Francesca Baglio Marzia Bedoni 《Journal of biophotonics》2020,13(3)
Alzheimer disease (AD) is the most common form of dementia in the elderly, progressively affecting the cognitive functions with a complex diagnostic procedure that limits the time for a prompt intervention. In this study we optimized a reliable protocol for the analysis of AD patients and healthy subjects' serum using the Surface Enhanced Raman Spectroscopy (SERS), taking into consideration the effect of different variables on the final spectra, analyzed and compared through multivariate analysis and correlated with hippocampus volume. As results, we demonstrated a statistical difference between the spectra collected from the two investigated groups, with an accuracy, precision and specificity of respectively 83%, 86%, and 86%. The correlation of these data with those obtained from MRI, demonstrated a direct correlation between Raman spectra and hippocampus degeneration showing the Raman Spectroscopy (RS) as a potential tool for the monitoring of AD progression and rehabilitation treatments. 相似文献
79.
80.
Schooling often rests uneasily on presumed dichotomies between coverage and inquiry, skill development, and creativity. By
drawing on the often under-recognized parallels between biological evolution and human learning, this essay argues that formal
education needs and ought not to forego the unconscious exploratory processes of informal learning. Rather than posit as natural
the cultural story that formal schooling must prepare students to integrate with given cultures and foreknowable futures,
the evolutionary perspective shows that education is better thought of as preparing students to create cultures and to change,
and foster change, in relation to unknown futures. The properties that distinguish formal from informal learning—conscious
reflection and a degree of collective consensus about what constitutes knowledge at any given time—are, we argue, useful not
as ends in themselves, but as tools for maximizing, sharing, and extending unconscious, evolutionary learning. Working with
them as such offers a way out of some of education’s persistent problems. Two autobiographical case studies provide examples
of these evolutionary changes and indicate pathways of inquiry by which to pursue them. 相似文献