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1.
H. B. Knight Lee P. Witnauer W. E. Palm R. E. Koos Daniel Swern 《Journal of the American Oil Chemists' Society》1959,36(9):382-388
Summary Thirty-one acyloxy or aryloxy esters prepared from hydroxystearic acids have been evaluated as plasticizers for a vinyl chloride-vinyl
acetate copolymer (95∶5). Many of them were found to be primary plasticizers, having outstanding low-temperature performance
when employed at the 35% level. Formulations with these compounds compared quite favorably in tensile properties with those
containing the di-2-ethylhexyl esters of phthalic, sebacic, azelaic, and adipic acids. Volatility losses were similar to those
of the four di-2-ethylhexyl esters. The loss of plasticizer through migration was equal to or less than that from compositions
containing the esters of sebacic, azelaic, and adipic acids but was greater than that of the phthalate ester.
A mechanistic scheme of plasticizer-polymer interaction has been presented, proposing that the rate of diffusion of plasticizer
through the polymer mass is a controlling factor in both good low-temperature performance and the resulting high migration
losses. Methyl esters, some aromatic esters, and esters containing three or more polar centers have improved permanence but
show a more rapid change in torsional modulus as the temperature is lowered during the determination of the Clash-Berg stiffening
temperature.
Eastern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture. 相似文献
2.
Edmund F. Jordan Steven Smith Ronald E. Koos Winfred E. Parker Bohdan Artymyshyn A. N. Wrigley 《应用聚合物科学杂志》1978,22(6):1509-1528
Compositionally and structurally varied copolymers all containing n-octadecyl acrylate were prepared and evaluated as viscosity index improvers in a common base oil under conditions of low shear. Systems evaluated over a range of copolymer and blend composition were: copolymers of n-octadecyl acrylate with, respectively, methyl methacrylate, 2-ethylhexyl acrylate, and n-dodecyl acrylate; and homopolymers of poly(n-octadecyl acrylate), prepared with a wide range of molecular weights. Properties were compared with those of blends of commercial methacrylate copolymers (acryloids) which had been freed of their entraining liquid. Mixtures of base oil with copolymers of n-octadecyl acrylate and methyl methacrylate, compared at fixed SAE viscosities, were the most efficient of all blends studied. They had the smallest rate of change of viscosity with temperature (as measured by their ASTM slopes), particularly in the composition region of incipient polymer precipitation at room temperature. Efficiency of certain of these composition was somewhat greater than that of the acryloids. A parameter that related concentration and weight-average molecular weight was used to correlate all of the data for ASTM slope and viscosity. Empirical relations developed by using this parameter enabled rheological data to be estimated that agree within 6% of experimental values for the case of thermodynamically good base oil solvents. These data demonstrated the relatively small contributions of copolymer structure to viscosity index improvement. 相似文献
3.
Britta Marko Paulina Heurich Patrick Thon Frieda Zimmer Lars Bergmann Hartmuth Nowak Katharina Rump Bjrn Koos Michael Adamzik Matthias Unterberg Tim Rahmel 《International journal of molecular sciences》2022,23(14)
The functionally important NF-κB1 promoter polymorphism (−94ins/delATTG) significantly shapes inflammation and impacts the outcome of sepsis. However, exploratory studies elucidating the molecular link of this genotype-dependent pattern are lacking. Accordingly, we analyzed lipopolysaccharide-stimulated peripheral blood mononuclear cells from both healthy volunteers (n = 20) and septic patients (n = 10). All individuals were genotyped for the −94ins/delATTG NF-κB1 promoter polymorphism. We found a diminished nuclear activity of the NF-κB subunit p50 in ID/DD genotypes after 48 h of lipopolysaccharide stimulation compared to II genotypes (p = 0.025). This was associated with higher TNF-α (p = 0.005) and interleukin 6 concentrations (p = 0.014) and an increased production of mitochondrial radical oxygen species in ID/DD genotypes (p = 0.001). Although ID/DD genotypes showed enhanced activation of mitochondrial biogenesis, they still had a significantly diminished cellular ATP content (p = 0.046) and lower mtDNA copy numbers (p = 0.010) compared to II genotypes. Strikingly, these findings were mirrored in peripheral blood mononuclear cells taken from septic patients. Our results emphasize the crucial aspect of considering NF-κB subunits in sepsis. We showed here that the deletion allele of the NF-κB1 (−94ins/delATTG) polymorphism was associated with the lower nuclear activity of subunit p50, which, in turn, was associated with aggravated inflammation and mitochondrial dysfunction. 相似文献
4.
Jan Oosterhaven 《Papers in Regional Science》1983,52(1):125-137
For land outside the sea-dikes of the northern part of the province of Friesland five alternative land-reclamation plans have been made. Agricultural organizations and the Province are in favour of the larger plans because of their expected economic benefits, which mainly accrue to arable farming — wholesale and processing. Environmental organizations are against these plans because of the expected damage to the valuable natural environment of the Dutch Shallows. The plans proposed primarily serve regional interests, have large indirect economic effects, and are finally decided upon by central government. It is argued that for an economic evaluation of such projects an integrated interregional cost-benefit and input-output analysis is most adequate. Under the present Dutch administrative and financial lack of decentralization, it appears to make a great difference whether the cost-benefit analyses are made from a regional point of veiw or made from the more usual national standpoint. 相似文献
5.
An interregional labour market model incorporating vacancy chains and social security 总被引:1,自引:0,他引:1
This paper deals with three aspects of interregional demo-economic models which are important with respect to the analysis of regional labour market developments. First, attention is paid to forecasts of the exogenous regional variables, such as investments, exports, etc. Because data at the regional level are usually scarce, it is suggested to make these projections by means of a top-down model. Second, the social security sector is incorporated in the model framework, because changes in social security benefits, which are common in many Western countries nowaday, usually have substantial impacts on regional economic and demographic structures. Third, a vacancy chain model instead of a simple employment growth equation is tied to the standard demo-economic model framework. In this way not only employment growth but also migration, job mobility and related income effects can be taken into account. 相似文献
6.
7.
8.
K Roessler K Ungersboeck M Aichholzer W Dietrich H Goerzer C Matula T Czech WT Koos 《Canadian Metallurgical Quarterly》1998,49(3):282-8; discussion 288-9
BACKGROUND: The Zeiss MKM System is a recently developed computerized operating microscope for image-guided neurosurgery. The clinical advantages, reliability, accuracy, and limitations of this technique were investigated. METHODS: Since February 1995, 78 consecutive frameless stereotactic image-guided procedures were performed in 73 patients (30 males, 43 females; mean age, 46.9 years; range, 16-77 years) for tumor surgery (50/64.1%), cavernoma removal (16/20.5%), and functional procedures (12/15.4%). Skin markers (74 cases) or bone markers (4 cases) and a standard imaging protocol (2-mm cranial computed tomography (CCT) in 59 cases/1.5-mm magnetic resonance imaging (MRI) in 19 cases) were used. RESULTS: The main advantages were pre-operative skin incision, craniotomy and corticotomy planning, and determination of lesion boundaries. Useful registration and system reliability were noted in 97% (76/78) of the procedures. A significant improvement in registration accuracy was observed over the test period from a mean of 4.8 mm (SD = 3.36; Cases 1-25) to a mean of 2.2 mm (SD = 0.86; Cases 26-78). This resulted in an improvement in application accuracy from <5 mm in 71% (Cases 1-25) to <2 mm in 95% (Cases 26-78) of cases, and the accuracy led to successful localization of the lesion in every case. Accuracy was reliable at the beginning of every procedure, but degraded to values >5 mm by the end of the procedure in 29% (22/78) of cases. MRI cases achieved higher application accuracy values (2.1 mm mean) than CT cases (3.7 mm mean). CONCLUSIONS: The system offers a reliable alternative to frame-assisted stereotactic craniotomies in lesion targeting, but would need an intraoperative image update for resection guidance. 相似文献
9.
OBJECTIVE: We determined the ability of capillary whole blood glucose concentrations to predict venous plasma and whole blood glucose levels. METHODS: During a standard oral glucose tolerance test in 29 pregnant women, paired capillary and venous blood samples were collected for analysis of glucose concentrations by the HemoCue photometer and by central laboratory methods. RESULTS: Glucose concentrations determined serially in a single blood sample by the HemoCue method were highly reproducible, with a coefficient of variation of 2.3%. However, glucose levels in blood from two different fingersticks from the same patient varied on average by 3 mg/dL, with a maximum difference of 14 mg/dL. Although capillary whole blood glucose results obtained by the HemoCue method correlated well with venous plasma or whole blood glucose measurements (r = 0.98 and r = 0.97, respectively) over the range investigated (60-250 mg/dL), individual capillary whole blood glucose measurements were only a fair predictor of venous values, with 95% of measured venous levels within +/- 26 mg/dL and +/- 20 mg/dL for concentrations predicted for plasma and whole blood, respectively. CONCLUSION: Sampling factors rather than measurement accuracy limit the ability of capillary whole blood glucose measurements to predict venous concentrations. 相似文献
10.
Observed the sexual behavior of 10 male rhesus monkeys before and after castration and during replacement therapy with testosterone propionate. In 10 tests before castration, all of the Ss ejaculated at least once, and in Weeks 21-25 and 51-55 after castration, 50 and 30%, respectively, ejaculated at least once. In the 35 postcastration tests given over a 55-wk period, 2 males did not ejaculate. 50% of the Ss achieved intromission 1 yr after castration. The percentage of castrated Ss showing intromission and ejaculation and the frequency of these responses were higher than those reported for most nonprimate species but did not differ greatly from those reported for the dog. Within 1 wk testosterone propionate restored whatever aspects of behavior were affected to precastration levels. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献