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11.
NITP (1) is an effective marker of hypoxia in tumours for both microscopy and cell sorting studies and, additionally, the compound shows post-irradiation sensitization, probably by inhibition of repair of radiation damage to DNA. However, NITP does not have the substitution pattern which the immunochemical reagents are raised to recognize and the compound has very low solubility in water. We report the synthesis of an isomer (13) of NITP which has the desirable substitution pattern and is also soluble in very weak aqueous base. The successful synthesis of 13 uses a nitrosation and cyclization of a substituted uracil (16), but earlier approaches from 5 and 12 yielded the pyridoxanthine derivative 6. The preparative use of nitro group displacement reactions from 8-nitrocaffeine is shown to be a useful entry to a range of 8-substituted caffeines and is utilized to obtain two derivatives of NITP which carry aliphatic amine chains, i.e. 34 and 35. 相似文献
12.
LK Malendowicz C Macchi GG Nussdorfer A Markowska 《Canadian Metallurgical Quarterly》1996,11(3):641-645
The effects of a prolonged administration of bradykinin (BK) and/or D-Arg, [Hyp3, D-Phe7]-BK, a specific antagonist of BK receptors (BK-A) (daily subcutaneous injections of 4 nmol/rat for 6 days) on the function of the pituitary-adrenocortical axis were investigated. BK did not change plasma aldosterone concentration (PAC), but markedly lowered that of corticosterone (PBC) and consequently induced a compensatory hypersecretion of ACTH by the pituitary gland. BK-A did not apparently affect the function and growth of the adrenal gland, but, when administered together with BK, markedly raised both PAC and PBC, and provoked a significant atrophy of the adrenal gland, probably due to loss of parenchymal cells. Taken together, these rather puzzling findings do not appear to provide clear evidence for the involvement of BK in the physiological regulation of adrenocortical growth and steroidogenic capacity in rats. 相似文献
13.
Through the study of the effects of concentration, temperature, and molar ration (of paraformaldehyde to cellulose) on solution viscosity and per cent transmittance (at 530 nm), it has been demonstrated that cellulose solutions in dimethyl sulfoxide (DMSO) are readily produced. By heating 1, 2, and 50 to 100 parts by weight of cellulose, paraformaldehyde, and DMSO, respectively, extremely viscose cellulose solutions and gels were prepared. Solutions with concentrations as high as 10% were prepared. However, the optimum conditions to effect complete cellulose solution in DMSO at 75°C were found to be 0.5% cellulose and 0.8 and 1.0% paraformaldehyde. This corresponds to a paraformaldehyde-to-cellulose molar ratio of about 10:1. 相似文献
14.
Nicholas J. Grant Earl C. Roberts John Chipman 《JOM Journal of the Minerals, Metals and Materials Society》1954,6(2):145-149
An equilibrium study was made of the distribution of chromium and oxygen between liquid iron, containing less than 1 pct Cr, and simple slags of the CaO(MgO)-SiO2-FeO-Cr2O3 type in the temperature range 1526° to 1734°C The effects of slag oxidation, temperature, and basicity were observed. 相似文献
15.
BACKGROUND: Do-not-resuscitate (DNR) orders for critically ill patients are frequently miscommunicated between attending physicians, house staff, and nurses. A computer-based system was developed to improve the communication of a procedure-specific DNR order form. METHODS: Concordance of understanding of patients' DNR status was measured with the use of unstructured DNR orders (period 1), procedure-specific DNR order forms (period 2), and procedure-specific DNR order forms administered with a computer-based communication system (period 3). The 3 components of the DNR order assessed were (1) the clinical events to which the DNR order applied, (2) whether the DNR order withheld all elements of cardiopulmonary resuscitation, and (3) whether other treatments were to be withheld. RESULTS: For the 147 patients, the computer-based system in period 3 (n = 71) improved concordance for attending physicians and nurses or residents for all 3 of the DNR components compared with period 1 (n = 40) and some of the DNR components compared with period 2 (n = 36). Concordance was "substantial" or "almost perfect" as measured by the K statistic during period 3. The proportion of agreement for the composite of all 3 components of the DNR order increased during each period (P<.001, period 3 vs period 1). Overall agreement between all caregivers for the composite DNR order also improved from period 1 (22.2%) to period 2 (47.8%) and period 3 (61.9%; P<.001 vs period 1). Errors in order entry were detected by physicians because of the computer system and corrected in 9.9% of DNR orders in period 3. Progress note documentation of DNR status did not improve during period 3. The procedures of period 3 were considered acceptable by the physician and nursing staff. CONCLUSION: A computer-based system combined with a procedure-specific DNR order form improves communication of patients' DNR status in a critical care setting. 相似文献
16.
GW Gao SH Lin YF Lin LK Diang KC Lu FC Yu SD Shieh 《Canadian Metallurgical Quarterly》1996,57(6):438-442
Despite a general national decline in criminal activities in the 1990s, juvenile criminal offenses continue to increase, (including violent, property, and delinquency acts). In addition increased numbers of children are being held in juvenile jails. It is all but impossible for pediatric health providers to think that "their patients" and "their practices" are immune from the epidemic of crime that affects and is caused by "just kids." 相似文献
17.
Contends that there are 3 methodological errors and an inconsistency in M. E. P. Seligman's (see record 1996-13324-001) reanalysis of the 1995 Consumer Reports survey of the effectiveness of psychotherapy. These errors are directly relevant to the cost-effectiveness of psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
A near-resonant, sway-induced sloshing flow in a rectangular tank is used to compare a homogeneous and inhomogeneous multiphase approach for fluid density and viscosity in a commercial CFD code. Dimensional analysis of the relative motion between the phases suggests the application of an inhomogeneous multiphase model whereas previous published work has used the computationally cheaper homogeneous (or average property) approach. The comparison between the computational and experimental results shows that the homogeneous model tends to underestimate the experimental peak pressures by up to 50%. The inhomogeneous multiphase model gives good agreement with the experimental pressure data. Examination of the relative velocity at the fluid interface confirms that the inhomogeneous model is the appropriate model to use for the simulation of a violent sloshing flow. 相似文献
19.
Abstract Some properties which have been useful in the computerized classification of white blood cells and breast tumors are compared to similar properties measured by human beings. It is shown that the computer properties need not be close approximations to the human properties for them to be valuable. 相似文献
20.
Understanding the influence of demographic and psychological variables on retirement planning. 总被引:1,自引:0,他引:1
The authors examined the degree to which workers were engaging in financial, health, interpersonal/leisure, and work planning for retirement, exploring whether demographic and psychological variables inhibited or promoted planning in each of these domains. Planning in each domain was influenced by a unique set of variables. Goals emerged as a consistent and positive predictor of planning. Gender accounted for health and interpersonal/leisure planning, while work planning behavior was negatively predicted by income. Time perspective also helped to clarify the amount of retirement planning undertaken in the financial and interpersonal/leisure domains. Practical implications for designing retirement interventions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献