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排序方式: 共有733条查询结果,搜索用时 15 毫秒
1.
Amino acid limited growth of starter cultures in milk 总被引:2,自引:0,他引:2
2.
A Jans E F Ippel P F Dijkstra J B Bijlsma 《Genetic counseling (Geneva, Switzerland)》1992,3(3):139-143
We report two sisters with mental retardation, coarse facial features, telecanthus, flat malar region, prominent lower lip, kyphoscoliosis, and tapering fingers. Although these patients' phenotypes showed considerable overlap with the Coffin-Lowry and the Atkin-Flaitz syndromes, their overall picture makes these diagnoses controversial. 相似文献
3.
This study compared Pundamilia nyererei and Pundamilia pundamilia males in routine metabolic rate (RR) and in the metabolic costs males pay during territorial interactions (active metabolic rate, RA). Pundamilia nyererei and P. pundamilia males housed in social isolation did not differ in RR. In contrast to expectation, however, P. nyererei males used less oxygen than P. pundamilia males, for a given mass and level of agonistic activity. This increased metabolic efficiency may be an adaptation to limit the metabolic cost that P. nyererei males pay for their higher rate of aggressiveness compared to P. pundamilia males. Thus, the divergence between the species in agonistic behaviour is correlated with metabolic differentiation. Such concerted divergence in physiology and behaviour might be widespread in the dramatically diverse cichlid radiations in East African lakes and may be an important factor in the remarkably rapid speciation of these fishes. The results did not support the hypothesis that higher metabolic rates caused a physiological cost to P. nyererei males that would offset their dominance advantage. 相似文献
4.
Influence of temperature on the number of Legionella pneumophila in hot water systems 总被引:1,自引:1,他引:0
The occurrence of legionella in the hot water systems of two buildings (A and B) was investigated in relation to the water temperature. The peripheral parts of both hot water systems were found to be colonized by these organisms. A temperature of 60C in the hot water mains returning from the building eliminated legionellas from the mains as well as from the peripheral taps and showers. Legionellas could be isolated from taps, showers and the mains when the temperature in the return mains was kept at 54C. The hot water systems could not be completely decontaminated by raising the hot water temperature in the return mains to 70C combined with flushing all the taps and showers. It is suggested that failure to decontaminate the systems is due to dead ends in the pipeline network, which are not reached by the hot water and that these dead ends are the source for recolonization of the systems. 相似文献
5.
Ronald J.A. Wanders Carlo Van Roermund Cor Lof Alfred J. Meijer 《Analytical biochemistry》1983,129(1):80-87
A simple fluorimetric assay for the determination of carbamoyl phosphate in tissue extracts is described. In the assay, production of ATP from carbamoyl phosphate and ADP by carbamate kinase is coupled to the formation of NADPH, using glucose, hexokinase, NADP+, and glucose-6-phosphate dehydrogenase. Production of NADPH in this system proved to be equal to the amount of carbamoyl phosphate present. 相似文献
6.
Frits Roerdink Jan Dijkstra Ger Hartman Ben Bolscher Gerrit Scherphof 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,677(1):79-89
125I-labeled albumin or poly(vinyl pyrrolidone) encapsulated in intermediate size multilamellar or unilamellar liposomes with 30–40% of cholesterol were injected intravenously into rats. In other experiments liposomes containing phosphatidyl[Me-14C]choline were injected. 1 h after injection parenchymal or non-parenchymal cells were isolated. Non-parenchymal cells were separated by elutriation centrifugation into a Kupffer cell fraction and an endothelial cell fraction. From the measurements of radioactivities in the various cell fractions it was concluded that the liposomes are almost exclusively taken up by the Kupffer cells. Endothelial cells did not contribute at all and hepatocytes only to a very low extent to total hepatic uptake of the 125I-labels. Of the 14C-label, which orginates from the phosphatidylcholine moiety of the liposomes, much larger proportions were recovered in the hepatocytes. A time-dependence study suggested that besides the involvement of phosphatidylcholine exchange between liposomes and high density lipoprotein, a process of intercellular transfer of lipid label from Kupffer cells to the hepatocytes may be involved in this phenomenon. Lanthanum or gadolinium salts, which effectively block Kupffer cell activity, failed to accomplish an increase in the fraction of liposomal material recovered in the parenchymal cells. This is compatible with the notion that liposomes of the type used in these experiments have no, or at most very limited, access to the liver parenchyma following their intravenous administration to rats. 相似文献
7.
Plant and Soil - In a recent framework, Raven et al. New Phytologist 217: 1420-1427. (2018) considered carbon cost of acquiring phosphorus by mycorrhizal and non-mycorrhizal plants. We broaden... 相似文献
8.
Tyler R. Funnell Robert J. Fialkowski Peter D. Dijkstra 《Ethology : formerly Zeitschrift fur Tierpsychologie》2022,128(1):15-25
In many group living animal species, individuals use aggression to gain and maintain social dominance to secure access to ecological resources and potential mates. While social dominance has many fitness benefits, there are also potential costs associated with frequent agonistic interactions and status display. One potential cost of social dominance is oxidative stress, the imbalance of reactive oxygen species and antioxidant capacity. In the cichlid species Astatotilapia burtoni, dominant males are aggressive, hold a breeding territory, and have an activated reproductive system resulting in larger gonads. Subordinate males are submissive, school with females, and are nonreproductive. Females are submissive under natural conditions, but in a female-only group, a dominance hierarchy will form with dominant females taking on male-typical behaviours including aggression, territory defence, and increased androgen levels. However, in contrast to males, social dominance is not linked to increased activation of the reproductive system in females, allowing us to test whether social dominance alone exposes individuals to increased oxidative stress. We compared dominant and subordinate females in female-only groups in five markers of oxidative stress. Dominant females did not have higher levels of oxidative damage compared to same-sex subordinates. This result contrasted to the trend in males in which dominant males had higher oxidative damage than their subordinate counterparts. Our findings suggest that the oxidative cost of social dominance is limited and support the notion that previously reported associations between high rank and increased oxidative stress is most likely driven by increased investment in reproduction. 相似文献
9.
Quirijn R. J. G. Tummers Charlotte E. S. Hoogstins Alexander A. W. Peters Cor D. de Kroon J. Baptist M. Z. Trimbos Cornelis J. H. van de Velde John V. Frangioni Alexander L. Vahrmeijer Katja N. Gaarenstroom 《PloS one》2015,10(6)
Objective
In ovarian cancer, two of the most important prognostic factors for survival are completeness of staging and completeness of cytoreductive surgery. Therefore, intra-operative visualization of tumor lesions is of great importance. Preclinical data already demonstrated tumor visualization in a mouse-model using near-infrared (NIR) fluorescence imaging and indocyanine green (ICG) as a result of enhanced permeability and retention (EPR). The aim of this study was to determine feasibility of intraoperative ovarian cancer metastases imaging using NIR fluorescence imaging and ICG in a clinical setting.Methods
Ten patients suspected of ovarian cancer scheduled for staging or cytoreductive surgery were included. Patients received 20 mg ICG intravenously after opening the abdominal cavity. The mini-FLARE NIR fluorescence imaging system was used to detect NIR fluorescent lesions.Results
6 out of 10 patients had malignant disease of the ovary or fallopian tube, of which 2 had metastatic disease outside the pelvis. Eight metastatic lesions were detected in these 2 patients, which were all NIR fluorescent. However, 13 non-malignant lesions were also NIR fluorescent, resulting in a false-positive rate of 62%. There was no significant difference in tumor-to-background ratio between malignant and benign lesions (2.0 vs 2.0; P=0.99).Conclusions
This is the first clinical trial demonstrating intraoperative detection of ovarian cancer metastases using NIR fluorescence imaging and ICG. Despite detection of all malignant lesions, a high false-positive rate was observed. Therefore, NIR fluorescence imaging using ICG based on the EPR effect is not satisfactory for the detection of ovarian cancer metastases. The need for tumor-specific intraoperative agents remains.Trial Registration
ISRCTN Registry ISRCTN16945066 相似文献10.
Cansu Y?ld?r?m Daphne Y. S. Vogel Maurits R. Hollander Josefien M. Baggen Ruud D. Fontijn Sylvia Nieuwenhuis Anouk Haverkamp Margreet R. de Vries Paul H. A. Quax Juan J. Garcia-Vallejo Anja M. van der Laan Christine D. Dijkstra Tineke C. T. M. van der Pouw Kraan Niels van Royen Anton J. G. Horrevoets 《PloS one》2015,10(4)