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排序方式: 共有535条查询结果,搜索用时 15 毫秒
81.
M Takamatsu M Tsunemoto Y Ota M Shimada T Shindo 《Canadian Metallurgical Quarterly》1976,29(6):421-425
Using sheep erythrocytes (SRBC) as the antigen, two subpopulations of spleen antigen-binding lymphocytes could be distinguished by a marked difference in the susceptibility of their receptors to trypsin. In unimmunized animals, 30% of the antigen-binding cells were trypsin-resistant, whereas at 5 days after immunization, 80-90% were trypsin-resistant, indicating an increase of about 50-fold in trypsin-resistant antigen-binding cells per spleen. In contrast, trypsin-sensitive cells per spleen were only 4-fold higher on day 5 than before immunization. The rise in % trypsin sensitivity preceded the increase in rosettes per spleen, implying that immunization produced a preferential increase in trypsin-resistant antigen binding cells partly by converting sensitive cells to resistant cells. After the 5th day, the trypsin sensitivity of antigen-binding cells slowly returned toward the unimmunized level, but a booster injection of SRBC restored trypsin resistance. Trypsin resistance was not lost in the presence of sodium azide or protein synthesis inhibitors. But a slightly increased trypsin susceptibility was conferred by 2-deoxyglucose, implying that glycolysis or the glycosylation of protein may be involved in maintaining trypsin resistance. 相似文献
82.
83.
The paper introduces a method of population estimation using the Landsat MSS data. The radiance in the four spectral bands, detected by the multi spectral scanner (MSS) depends upon the ground covering materials, albeit the land use of the area. A mathematical model is set up to express the relation between the reflected electromagnetic energy of sample areas and their population distribution. Landsat 1 and Landsat 3 data of the Kanto area (including Tokyo Metropolitan), acquired in 1972 and 1979, are used along with ground-based census data of 1970 and 1975 to monitor the population distribution and its temporal changes. The method provided a reliable assessment of the population density in residential zones, however land-use classification using MSS imagery previous to the modeling is expected to improve the results. 相似文献
84.
The aim of the present study was to evaluate the effect of human follicle stimulating hormone (hFSH) on cellular proliferation in the chick embryo ovary. Chick embryos (Babcock B300) were injected on chorioallantoic membrane with a single dose of hFSH (2.0 IU/ embryo) at Days 7, 9, or 13 of incubation or with hCG (2.0 IU/embryo) at Day 13 of incubation. At 17 days of incubation and within 24 h after hatching, left ovaries were dissected and completely dissociated. Cells from the whole ovary were classified into germ cells (primary oocytes), typical steroidogenic cells, and poorly differentiated somatic cells and counted with the aid of a hemocytometer. Aliquots of the cell suspension from the whole left ovary were analyzed by flow cytometry, in order to determine the percentage of cells at each phase of the cell cycle. In addition, samples of the suspension (1.0 x 10(6 )cells) were incubated for 2 h in basal and stimulated conditions measuring 17beta-estradiol secretion in the medium. The ovarian cell number at 17 days of incubation showed that hFSH treatment at Day 7 did not modify the cell number in any of the subpopulations evaluated; treatment at Day 9 resulted in an increase in poorly differentiated somatic cell number, without changes in steroidogenic and germ cells, whereas hFSH treatment at Day 13 augmented the number of poorly differentiated, steroidogenic, and germ cells. The percentage of cells in S-phase was increased 12 and 15 h after hFSH treatment (Day 13). Secretion of 17beta-estradiol was increased in the hFSH-treated group (Day 13) measured at 17 days of incubation. The increase in cell number of the three subpopulations was still observed in the left ovary of the newly hatched chicken. Treatment with hCG at Day 13 of incubation did not change the number of poorly differentiated, steroidogenic, and germ cells in the left ovary, neither in the 17-day-old chick embryo nor in the newly hatched chicken. The 17beta-estradiol secretion in hCG-treated embryos was similar to controls. The present study is the first evidence of an effect of FSH on somatic and germ cell number, together with an increase in 17beta-estradiol production during chick embryo ovary development. 相似文献
85.
Isolation and identification of a cardioactive peptide from Tenebrio molitor and Spodoptera eridania
K Furuya S Liao SE Reynolds RB Ota M Hackett DA Schooley 《Canadian Metallurgical Quarterly》1993,374(12):1065-1074
We isolated several cardioactive peptides from extracts of whole heads of the mealworm, Tenebrio molitor, and the southern armyworm, Spodoptera eridania, using a semi-isolated heart of Manduca sexta for bioassay. We have now isolated from each species the peptide with the strongest effect on rate of contraction of the heart. The peptides were identified using micro Edman sequencing and mass spectrometric methods. This cardioactive peptide has the same primary structure from both species: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2, a cyclic nonapeptide which is identical to crustacean cardioactive peptide (CCAP) originally isolated from the shore crab, Carcinus maenas, and subsequently isolated from Locusta migratoria and Manduca sexta. This is additional evidence that CCAP has widespread occurrence in arthropoda. 相似文献
86.
PURPOSE: The purpose of this study was to gain information about the employment status of legally blind patients. METHODS: Fifty-two patients with one of four juvenile-onset macular dystrophies or achromatopsia responded to questions about their employment histories and their psychological well-being. Results from the questionnaire were analyzed using z-tests for differences in proportions or t-tests for differences in means. RESULTS: Forty-eight percent of the patients reported that they were employed and 52% that they were not employed. The subgroup that was not employed had a significantly higher proportion of women than men, whereas the employed group had approximately equivalent proportions of men and women. The employed subgroup reported that their success at work was due to social support. This subgroup had significantly higher household incomes, was significantly less likely to collect disability-income benefits, had significantly higher educational levels, had significantly higher positive affect, and had significantly lower negative affect than the subgroup that was not employed. A logistic regression analysis indicated that education was the primary predictor of employment. CONCLUSION: Analysis supports the conclusion that it is beneficial for legally blind individuals to obtain an optimal level of education and receive suitable social support to facilitate their successful employment. 相似文献
87.
The membrane fluidity characteristics of multilamellar (MLV) and extruded liposomes prepared with kaempferol (K), kaempferol-3-glucoside (KG), (−)-epigallocatechin (EGC) or (−)-epigallocatechin-3-gallate (EGCG) are presented. Kaempferol caused the highest increase in fluorescence polarisation of DPH in both liposomes (other compounds had not) indicating that K with nK/nLip below 0.2 or 0.1 decreased the membrane fluidity, while at higher molar ratios the membrane fluidity increased. EPR measurements with MLV and spin probes MeFASL(10,3) and MeFASL(2,11) showed a significant decrease in fluidity in the upper part of the membrane for all flavonoids measured, and in the core of the membrane an increase in fluidity for EGCG and EGC. Computer simulation of the EPR spectra showed that the membrane of the MLV used was composed of at least three coexisting domain types with different fluidity and that the order parameter of the most ordered domains is responsible for membrane fluidity alterations. 相似文献
88.
Ichiro Imae Shotaro Takayama Daisuke Tokita Yousuke Ooyama Kenji Komaguchi Joji Ohshita Takashi Sugioka Koichi Kanehira Yutaka Harima 《Polymer》2009,50(26):6198-6201
Bis(triethoxysilyl)-substituted oligothiophene with a moderate π-conjugation length was newly synthesized and polymerized to give a polysilsesquioxane network having oligothiophene units dispersed homogeneously without phase separation. The polymer was fixed on glass or ITO substrate by spin-coating and annealing. The resulting film exhibited a high mechanical strength due to the covalent bonding with the substrates, and was electrochemically stable even after 300 redox cycles in electrolyte solution. Chemical oxidation of the polymer films yielded electrically conductive and almost transparent films. 相似文献
89.
Wearable Devices: Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring (Adv. Mater. 39/2017) 下载免费PDF全文
90.