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排序方式: 共有2384条查询结果,搜索用时 15 毫秒
21.
WC Widrich AH Robbins DC Nabseth ET O''Hara WC Johnson KV Loughlin 《Canadian Metallurgical Quarterly》1976,121(2):295-302
A series of ergot alkaloids, together with the DA agonists apomorphine and piribedil, were tested for protective effects against audiogenic seizures in an inbred strain of mice (DBA/2) and for induction of circling behaviour in mice with unilateral destruction of one nigrostriatal DA pathway. The order of potency against audiogenic seizures was apomorphine greater than ergocornine greater than bromocryptine greater than ergometrine greater than LSD greater than methysergide greater than piribedil while that observed in the rotating mouse model was apomorphine greater than ergometrine greater than ergocornine greater than bromocryptine greater than piribedil. LSD caused only weak circling behaviour even when administered in high doses (greater than 1 mg/kg). Methysergide was ineffective. Prior administration of the neuroleptic agent haloperidol blocked the effect of DA agonists and of ergot alkaloids in both animal models. The possible action of ergot alkaloids as DA agonists is discussed. 相似文献
22.
EP Lautenschlager GW Marshall KE Marks J Schwartz CL Nelson 《Canadian Metallurgical Quarterly》1976,10(6):837-845
Admixing of several antibiotic powders which were insoluble in methyl methacrylate did not decrease the compressive and diametral tensile strengths of two acrylic bone cements when tested after setting for 1 day and after leaching 40 days in water at 37 degrees C. When antibiotics were added as water solutions, the included water resulted in a significant decrease in these bulk mechanical properties. Storage in water for 40 days caused surface irregularities only on specimens of the set antibiotic admixtures. Approximately 0.5% of the admixed dosage of these water-soluble antibiotics could be leached from the set cements. The observed surface channels, presumably left by the loss of antibiotic, suggest further study of surface-sensitive mechanical properties may be needed. The bulk mechanical strengths presented here are conclusive only for the particular combinations of antibiotics and cements investigated, and should not be generalized at this time to any or all antibiotic admixtures or other mechanical properties. 相似文献
23.
S Duca A Suiu I Szantay C Duca R Lezeu M Schwartz H Szilagyi 《Canadian Metallurgical Quarterly》1976,26(5):858-862
Accumulation of radioactive material in the isolated rat liver was noted when 125I-fibrinogen was added to the perfusing medium. Owing to an enhanced production of fibrinogen and to a diminished fibrinolysis, fibrin deposits were found to occur in the capillaries of fhe isolated liver. This would cause a decrease of hepatic flow and an impairment of the nutrition of this organ which leads to subsequent necrosis. Administration of streptase removed the fibrin deposits and restored the perfusive flow in the isolated liver. 相似文献
24.
Two cases of juvenile gastrointestinal polyposis are described and the literature is reviewed. Despite the benign nature of the individual polyps, the disease has a poor prognosis. Of 13 reported patients, 4 had macrocephaly, and one of the authors' 2 patients had large peripheral intracranial cysts. This appears to be the first reported documentation of the etiology of macrocephaly associated with juvenile polyposis. Major clinical problems are related to severe loss of blood and protein from the gastrointestinal tract. 相似文献
25.
GL Johnson RA Meyer DC Schwartz J Korfhagen S Kaplan 《Canadian Metallurgical Quarterly》1976,38(5):611-619
Left ventricular function was evaluated echocardiographically within 24 hours of cardiac catheterization in 45 children with fixed aortic stenosis. Left ventricular systolic time intervals, mean velocity of circumferential fiber shortening, left ventricular end-diastolic volume and shortening fraction were evaluated. Some patients with severe aortic stenosis had a shortened preejection period, prolonged ejection time and increased mean velocity of circumferential fiber shortening in comparison with normal subjects, but these findings were not consistent within the group with severe aortic stenosis or apparent in patients with mild or moderate aortic stenosis. Left ventricular end-diastolic volume was smaller in children with severe obstruction than in normal children. Evaluation of the shortening fraction provided good separation of patients with significant obstruction from those with mild disease. Further, there was a linear correlation between the shortening fraction and the left ventricular-aortic gradient demonstrated at cardiac catheterization. This correlation was also of use in evaluating the response of patients to surgical relief of obstruction. Pre- and postoperative echocardiographic evaluation of the shortening fraction appears to provide a readily available noninvasive method of assessing the course and severity of obstruction in fixed aortic stenosis in children. 相似文献
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28.
MR Cohen E Hinsch R Vergona J Ryan SJ Kolis MA Schwartz 《Canadian Metallurgical Quarterly》1976,197(3):697-702
Intravenous dose-response data obtained from renal clearance studies in anesthetized dogs indicated that bumetanide was approximately 30-fold more potent than furosemide in enhancing sodium excretion. After the administration of 0.01 mg/kg of bumetanide or 1.0 mg/kg of furosemide, the relationship between i.v. diuretic activity and tissue distribution was evaluated. In dog renal clearance experiments, bumetanide and furosemide significantly enhanced urine flow, sodium and potassium excretion. Inulin clearance as an estimate of glomerular filtration rate was not altered by either drug, but sodium reabsorption was decreased with bumetanide (13%) and furosemide (12%). At these diuretic doses, both compounds were bound to dog plasma protein to about the same extent (86-91%), although total plasma levels were 100-fold higher for furosemide. Within 1/2 hour after the i.v. administration of 14C-bumetanide or 14C-furosemide, 86 to 99% of the 14C in urine, plasma, kidney, and liver appeared as unchanged drug. One minute after maximal diuresis bumetanide was found to have a higher affinity (3-fold) for kidney compared to furosemide. These data offer a possible explanation for the i.v. diuretic potency difference between these two compounds. Furthermore, the lack of significant difference in plasma protein binding and the absence of urinary metabolites of either drug suggest that other factors may also contribute to the marked differences in diuretic activity between bumetanide and furosemide. 相似文献
29.
A multiplex polymerase chain reaction was developed to simultaneously identify Listeria monocytogenes and species of the genus Listeria. Two sets of primers were used, with the first amplifying a 938-bp region of the 16S rRNA gene that is highly conserved in all Listeria species and the second amplifying a 174-bp region of the listeriolysin (hlyA) gene of L. monocytogenes. Thus, isolates of Listeria spp. yield a single 938-bp product, whereas L. monocytogenes isolates yield both the 938-bp product and a 174-bp product. The specificity of the assay was verified with all six Listeria species and 11 serotypes of L. monocytogenes, as well as nonrelated bacteria. The multiplex PCR assay was used to determine the incidence of Listeria spp., especially L. monocytogenes, in mechanically separated turkey samples (n = 150 samples). L. monocytogenes strains were selected by using the University of Vermont two-step enrichment protocol and plating to selective Palcam agar. The multiplex PCR assay was used for verification of presumptive Listeria colonies. Approximately 38% of mechanically separated turkey samples (57 of 150) yielded L. monocytogenes; an additional 18% of these samples (27 of 150) harbored other Listeria spp. Fifty-one percent (29 of 57) of the L. monocytogenes isolates were of serogroup 1, 44% (25 of 57) were of serogroup 4, and 2% (1 of 57) were assigned to serogroups other than 1 and 4. 相似文献
30.
Eunice Valduga Cátia Regina Martin Schwartz Pihetra Oliveira Tatsch Lídia Tiggemann Marco Di Luccio Helen Treichel 《European Food Research and Technology》2011,232(3):453-462
This study aimed at optimising the cultivation conditions for the production of carotenoids by Sporidiobolus salmonicolor (CBS 2636) in a bioreactor. The maximum content of total carotenoids in the full factorial design 22 was 3131.3 μg/L in synthetic
medium with 80 g/L of glucose, 15 g/L of peptone, 5 g/L of malt extract, aeration of 1.5 vvm, agitation of 180 rpm, initial
pH of 4.0 at 25 °C. In the kinetic study, we could observe that the bioproduction of carotenoids is associated with cell growth
in the exponential phase, and the average specific growth (μ) in bioreactor is 0.046 h−1 with a maximum yield of 0.19 g cells/L h. The maximum yield of carotenoids (60.0 μg/Lh) is observed at 50-h bioproduction.
The conversion factor for total organic carbon (TOC) in cells (YX/SCOT) was 2.97 g/g (0–50 h) and 0.254 g/g (50–100 h), the conversion factor glucose into cells (YX/Sglicose) was 0.168 g/g (0–100 h). The specific production of carotenoids (YP/X) was 390 μg of carotenoids per gram of cells, the conversion factor of carbon in the product (YP/SCOT) was 107.8 μg/g (0–50 h) and 34.4 μg/g (50–100 h), whereas the factor YP/Sglicose was 69.59 μg/g. The agitation and aeration provided better homogeneity in the culture medium, and hence greater availability
of nutrients and oxygen, leading to higher production of carotenoids. 相似文献