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1.
Estracyt, a compound of nitrogen-mustard linked to oestradiol phosphate, is used in the treatment of human prostatic cancer. The metabolism of this compound has been studied in different tissues of the rat both in vivo and in vitro. The phosphate group in position 17 of the oestradiol moiety is rapidly split off from the compound. An oestrone-cytostatic compound was extractable from the liver half an hour after the injection of Estracyt. In addition the in vitro results showed that only the liver was able to convert the oestradiol-cytostatic compound to an oestrone-cytostatic one. When animals were killed 24 h after a 3-day period of Estracyt treatment, the dominating metabolite in the ventral prostate was an oestronecytostatic compound, but traces of free oestrone could also be demonstrated. No such compound, however, was found in liver, diaphragm or blood at this time. It is concluded that in vivo an oestrone-cytostatic compound seems to be preferentially retained in the ventral prostate after Estracyt injection whilst the metabolic conversion of the oestradiol-cytostatic compound into an oestrone-cytostatic one possibly occurs in the liver.  相似文献   

2.
针对常用的紫铜风口耐磨性差,使用寿命较短,开发了一种新型的复合风口制造技术,即在风口工作部位,通过爆炸焊接技术复合耐磨合金层。工业应用表明,复合风口使用寿命明显延长,使用安全可靠,具有良好的推广应用前景。  相似文献   

3.
The spectrofluorimetric method of bez(a)pyrene was used without separating it from other polycyclic aromatic hydrocarbons. On the basis of that method the content of that compound was measured in air contaminated with gas after burning of gas cookers. The study showed that this compound is not present in Warsow when earth gas is burning, but burning of propane-butane mixture contaminates air with this compound in a considerable degree.  相似文献   

4.
Pigeons initially trained to match using element samples and element comparisons demonstrate reduced matching accuracy on trials in which the sample is a compound stimulus. Two interpretations of this phenomenon, the shared attention account and the coding decrement account, were assessed in 3 experiments with 8 Silver King pigeons. Exp I obtained the typical outcome of reduced matching accuracy to compound samples following training to match to element samples. However, in a 2nd group trained initially to match to compound samples, Ss matched more accurately on compound sample trials than on element sample trials. Sample duration was manipulated in Exp II, and Ss were tested on simultaneous and 0-sec delayed matching trials in Exp III. Neither manipulation influenced the magnitude of the element–compound difference in either group. It is concluded that the coding decrement interpretation best accounts for these and other findings on matching to element and compound samples in pigeons. This account holds that (a) pigeons do not decompose compound samples; (b) presentation of a familiar sample activates a code; and (c) a novel sample that is sufficiently similar to a sample that activates a code will also tend to activate that code. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

5.
Proquazone, 1-isopropyl-4-phenyl-7-methyl-2(1H)-quinazolinone is an orally effective anti-inflammatory analgesic and antipyretic compound in animal models. The compound is less ulcerogenic than indomethacin in the rat and appears to potentiate the anti-inflammatory and thymus involution effects of hydrocortisone in this species. That a nonacidic nonsteroidal compound would display a spectrum of anti-inflammatory activity similar to that previously found only with acidic compounds will be the subject of further investigations.  相似文献   

6.
[Correction Notice: An erratum for this article was reported in Vol 37(2) of Journal of Experimental Psychology: Animal Behavior Processes (see record 2011-08162-003). There was an error in Figure 3, which is described in the correction.] Four experiments showed that the preference normally established to a neutral flavor cue that was paired with maltodextrin was attenuated when that cue was conditioned in compound with another flavor—overshadowing. Furthermore, two experiments showed that the preference for a neutral flavor conditioned as part of a compound was further attenuated if the other element in that compound was separately paired with the reinforcer—blocking. These results stand in contrast to a number of previous compound flavor preference conditioning experiments, which have not revealed reliable cue competition effects. These discrepant findings are discussed in terms of the effects of within-compound associations and a configural perspective on potentiation. Modeling of this configural perspective predicts that a compound of two separately trained cues will elicit a similar response to the individual cues themselves—absence of summation. Two experiments confirmed this prediction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

7.
8.
In studies reporting stimulus-reinforcer interactions in traditional conditioning paradigms, when a tone-light compound was associated with food the light gained stimulus control, but when the compound was paired with shock avoidance the tone gained control. However, the physical nature of the reinforcer-related events (food vs. shock) presented in the presence of the tone-light compound was always confounded with the conditioned hedonic value of the compound's presence relative to its absence. When the compound was paired with shock, its presence was negative relative to its absence (which was shock-free). In contrast, when the compound was paired with food, its presence was positive relative to its absence (which was food-free). The present experiment dealt with this confounding effect by conditioning a tone-light compound to be positive or negative, relative to its absence, solely with food reinforcement. One group of rats received food for responding in the presence of the tone-light compound and no food in its absence. The other group also responded in the presence of the compound, but received food only in its absence. These rats were trained on a chained schedule in which responding in the presence of the tone-light compound produced a terminal link signaled by the absence of the compound; responding ceased in the terminal link because it delayed food delivery. In a test session to assess stimulus control by the elements of the compound, tone and light were presented separately under extinction conditions. Rats that had been exposed to a positive correlation between food and the compound emitted almost double the responses in the presence of the light as in the presence of the tone. In comparison, rats that had been exposed to a negative correlation emitted only two thirds as many responses in the presence of the light as in the presence of the tone. Because this selective association was produced using only food, it appears that the contingencies under which a reinforcer is presented, rather than (or as well as) its physical properties, can generate the selective associations previously attributed to "stimulus-reinforcer interactions." This could mean that regardless of the class of reinforcer that ultimately maintains responding (appetitive or aversive), the contingency-generated hedonic value of the compound stimulus may influence the dominant modality of stimulus control.  相似文献   

9.
Tomoxiprole is a nonsteroidal anti-inflammatory compound that was reported to have low ulcerogenic potential, a quality that would be expected of a cyclooxygenase-2-selective inhibitor, and, in fact, we find it is selective for this isozyme. In stably transfected COS cells, the compound inhibits recombinant human cyclooxygenase-2 (IC50 = 7 nM) more potently than recombinant cyclooxygenase-1 (IC50 = 240 nM), and similar results are obtained with partially pure ovine enzyme preparations. The compound is thus a very potent as well as selective inhibitor of cyclooxygenase-2. As is true of some other cyclooxygenase-2-selective inhibitors, tomoxiprole inhibition of cyclooxygenase-2 but not cyclooxygenase-1 is time-dependent.  相似文献   

10.
Reports an error in "Cue interactions in flavor preference learning: A configural analysis" by Dominic M. Dwyer, Mark Haselgrove and Peter M. Jones (Journal of Experimental Psychology: Animal Behavior Processes, 2011[Jan], Vol 37[1], 41-57). There was an error in Figure 3. The X-axis of both panels of this figure should be labeled “3-trial block” and not “trial.” The analysis of the simulations presented in Figure 3 are unaffected by this change. The corrected figure is provided in the erratum. (The following abstract of the original article appeared in record 2011-01268-001.) Four experiments showed that the preference normally established to a neutral flavor cue that was paired with maltodextrin was attenuated when that cue was conditioned in compound with another flavor—overshadowing. Furthermore, two experiments showed that the preference for a neutral flavor conditioned as part of a compound was further attenuated if the other element in that compound was separately paired with the reinforcer—blocking. These results stand in contrast to a number of previous compound flavor preference conditioning experiments, which have not revealed reliable cue competition effects. These discrepant findings are discussed in terms of the effects of within-compound associations and a configural perspective on potentiation. Modeling of this configural perspective predicts that a compound of two separately trained cues will elicit a similar response to the individual cues themselves—absence of summation. Two experiments confirmed this prediction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

11.
OBJECTIVES: The objective of this study was to demonstrate the impact of the sum of parent compound and metabolite in bioequivalence assessment. METHODS: Four drugs with active metabolite were selected to assess bioequivalence. Bioequivalence criteria of 80 - 125% were applied to the parent compound, the metabolite, and the sum of parent compound and metabolite. RESULTS: The results indicated that the application of 80 - 125% bioequivalence criteria to the sum of parent compound and metabolite might be misleading. CONCLUSION: The 90% confidence interval should be applied separately to the parent compound and each metabolite.  相似文献   

12.
在剖析了PID控制及FUZZY控制原理和优缺点之后,提出一种新的复合自适应FUZZY-PID控制算法,并对其进行了仿真实验。在此基础上研制出复合自适应FUZZY-PID控制器。混合仿真实验和可靠性实验都证明了该控制器的性能是优越的。  相似文献   

13.
1-Hydroxy-2-naphthoate (compound I) is a metabolite of the phenanthrene-degradative pathway in Nocardioides sp. strain KP7. This singly hydroxylated aromatic compound is cleaved by 1-hydroxy-2-naphthoate dioxygenase. In this study, the structure of the ring cleavage product generated by the action of homogeneous 1-hydroxy-2-naphthoate dioxygenase was determined upon separation by high-performance liquid chromatography at pH 2.5 by using nuclear magnetic resonance (NMR) and mass spectroscopic techniques. The ring cleavage product at this pH existed in equilibrium between two forms, 2-oxo-3-(3-oxo-1,3-dihydro-1-isobenzofuranyl)propanoate (compound III) and 2,2-dihydroxy-3-(3-oxo-1, 3-dihydro-1-isobenzofuranyl)propanoate (compound IV). After the pH of the solution was raised to 7.5, the structure of the major species became (E)-4-(2-carboxylatophenyl)-2-oxo-3-butenoate (compound II; common name, trans-2'-carboxybenzalpyruvate), which was in equilibrium with compound III. Direct monitoring of the enzymatic formation of the ring cleavage product by 1H-NMR in a deuterated potassium phosphate buffer (pH 7.5) detected only compound II as a product, and the proton on carbon 3 of compound II was not exchanged with deuterium. Thus, compound II is likely to be the first stable product of dioxygenation of 1-hydroxy-2-naphthoate.  相似文献   

14.
Replacement of the noragmatine group in thrombin inhibitors with a beta-alanyl-guanidine group resulted in a nearly equipotent and more selective compound 8 despite the fact that the pKa of this P1 moiety is five orders of magnitude lower. Further modification resulted in a nonpeptide inhibitor with this beta-alanyl-guanidine group, compound 28. This is an active and selective thrombin inhibitor and in view of its nonpeptide/low basicity structure selected for further pharmacological studies.  相似文献   

15.
16.
The role of semantic transparency in morphological processing in general and in compound processing in particular is examined. It is argued that the notion of semantic transparency is crucial to an account of how compounds are represented and processed in the mind. A sketch of a model is proposed in which compound processing is described in terms of stimulus properties, lexical properties, and conceptual properties. The model represents the notion of semantic transparency in terms of a four-way classification of the semantic relationship between a compound's constituents and the corresponding independent morphemes. It also distinguishes between semantically componential and noncomponential compounds. It is proposed that the model offers a framework within which experimental psycholinguistic findings can be understood and within which aphasic deficits associated with compound processing can be characterized. As an example of this, the paper presents a reanalysis of an aphasic patient who exhibits the tendency to interpret semantically opaque compounds as though they were transparent and to interpret opaque compounds in terms of a blend of constituent and whole-word meaning. It is argued that the underlying deficit in this patient is the failure for inhibition to result from the competition among stimuli at the conceptual level of representation.  相似文献   

17.
研究了复合添加剂MnO2、MgO和Y2O3对Al2O3陶瓷烧结性和抗热震性的影响.试验结果表明:在复合添加剂中引入MgO和Y2O3大幅度提高了Al2O3陶瓷的致密度,促进了陶瓷的烧结,提高了材料的强度.Al2O3陶瓷的抗热震性能也得到提高,当MgO和Y2O3的含量为0.5%时,Al2O3陶瓷的临界热震温差在300℃左右,抗热震性能大大提高;继续增加MgO和Y2O3的含量,其抗热震性有所降低.添加复合添加剂的Al2O3陶瓷的抗热震性受到细晶强化和气孔的共同控制,对抗热震性提高的主要贡献为细晶强化,但气孔也会影响其抗热震性.  相似文献   

18.
Compound channels are often constructed in restoration projects on rivers and streams that have been channelized or are deeply incised. This design allows for flow over a wider cross-sectional area during high flows and is expected to reduce both flow velocities and bed-shear stresses in the channel during high flows. Using a compound channel restoration project on Tassajara Creek as a case study, the effectiveness of a constructed compound channel in reducing channel velocities and bed-shear stresses during high flow events was tested in two ways. First, since this is an a posteriori analysis, postproject surveys and assessments of the project are used to demonstrate the geomorphic and ecological benefits of the constructed compound channel for reducing further channel incision, improving channel stability, and enhancing native riparian vegetation, while still providing conveyance capacity for design flood flows. Second, the effectiveness of a constructed compound channel in reducing channel velocities and bed-shear stresses during high flow events is evaluated using both the one-dimensional (1D) model, HEC-RAS, and the three-dimensional (3D) numerical model, UnTRIM. This analysis demonstrates that the 1D analysis does not accurately portray the benefits of the compound channel, and is therefore not a suitable tool for evaluating the effectiveness of compound channel designs. These results demonstrate the advantages of using a 3D model and make a strong case for the implementation of more detailed hydrodynamic modeling in evaluating the suitability of restoration alternatives to improve the planning and design of river restoration projects.  相似文献   

19.
Alloying effects on the electronic structure of a TiAl compound have been investigated systematically using the discrete variational (DV) Xα cluster calculation. It has been shown that the existence of directional Al p-Ti d covalent bonds causes this compound to be brittle. The addition of those elements into TiAl which weaken p-d interactions but enhance d-d interactions is most effective in improving the ductility.  相似文献   

20.
It has previously been shown that Lactobacillus fermentum strain 104r releases compounds into its culture fluid that inhibit the adhesion of enterotoxigenic Escherichia coli K88. The aim of the present study was to purify and identify this compound. Judged by gel filtration, the compound was found to be approximately 1700 kDa. The amount of active compound increased upon prolonged incubation, while the number of viable cells reduced, suggesting that the activity was coming from dead cells. As the activity can be destroyed by lysozyme treatment and contains glucose, N-acetylglucosamine and galactose, it was concluded that cell wall fragments are the active agent, although cell wall preparations did not have the same effect. Adhesion to some mucus fractions could be inhibited by spent culture fluid, indicating specific interaction between mucus and the active compound. The compound was not able to interfere with the adhesion of E. coli 1107 to neutral lipids from mucus which contain a glycolipid receptor for K88 fimbriae.  相似文献   

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