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81.
In our previous work, we reported that cationic water‐soluble pressure‐sensitive adhesives (PSAs) could be synthesized in ethanol or methanol. These cationic water‐soluble adhesives would not cause a stickies problem during paper recycling and can be easily removed from the papermaking system by adsorbing on wood fibers. In this study we report the synthesis and application of water‐based cationic PSAs using miniemulsion polymerization. A redox initiator system of cumene hydroperoxide/tetraethylenepentamine was used to force interfacial polymerization. The end‐use properties of the PSAs were evaluated, and the repulpability of the PSAs in paper recycling was studied. It was found that the cationic PSA from miniemulsion polymerization itself was insoluble and nondispersible in water during the paper recycling process. However, if this water‐insoluble cationic PSA from miniemulsion was formulated with a water‐soluble cationic PSA made from ethanol, the solubility or dispensability of the former PSA in water was improved. The molecular weight and degree of crosslinking of the PSA polymer have significant effects on the properties and dispersability of PSA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 347–353, 2004 相似文献
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In a prospective study at a single centre between August 1995 and March 1996, 193 patients with elbow injuries were studied. Standard radiographs of the elbows were taken. A total of 181 X-rays were reported by one person concerning the presence or absence of fractures and fat-pad signs. The radiographs were analysed and positive predictive values were calculated for the presence of the fat-pad sign with radial head/neck fractures. The sensitivity for radial head/neck fracture is 85.4 per cent, while the specificity is only 50 per cent. The fat-pad sign must be used cautiously as an indicator of radial head/neck fractures; its absence is a more reliable indicator of the absence of a radial head/ neck fracture. 相似文献
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YR Ortega CR Roxas RH Gilman NJ Miller L Cabrera C Taquiri CR Sterling 《Canadian Metallurgical Quarterly》1997,57(6):683-686
Cryptosporidium parvum and Cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. Cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms of transmission of Cyclospora cayetanensis have not been fully determined. Humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. Samples of vegetables were collected at several small markets in a periurban slum in Peru during the seasons of high and low incidence. The vegetables were washed, the supernatants were collected and centrifuged, and the pellets were resuspended in a solution of 2.5% potassium dichromate. Pellets were examined using direct microscopic observation, acid-fast staining, and immunofluorescent assays for C. parvum and Cyclospora cayetanensis oocysts. Samples were collected during three time periods: the season of low incidence, the beginning of the season of high incidence, and end of the season of high incidence. Of the total vegetables examined, 14.5% contained C. parvum oocysts and 1.8% had Cyclospora oocysts. Thus, market vegetables may provide a route by which Cryptosporidium and Cyclospora can be transmitted. Our study also suggests that washing vegetables does not completely remove Cryptosporidium and Cyclospora oocysts. 相似文献
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NJ Lygidakis G Dedemati N Spenzaris M Theodoropoulou 《Canadian Metallurgical Quarterly》1997,44(16):1222-1228
BACKGROUND/AIMS: The aim of this study was to evaluate the combination of immunochemotherapy and stop-flow upper abdominal chemotherapy in the prolongation of survival in patients with unresectable pancreatic cancer. METHODOLOGY: Thirty unresectable pancreatic cancer patients were treated with immuno-chemotherapy in combination with stop-flow upper abdominal chemotherapy, in an attempt to improve survival time. RESULTS: The results obtained in this study indicate that this kind of treatment is feasible, safe and effective for patients suffering from Stage III and IV pancreatic duct carcinoma. Twenty per cent of the patients within this group were able to undergo radical resection and remain alive and free of disease, with a mean survival rate of 16 months. CONCLUSION: The multi-modality approach used in this study achieved promising results for pancreatic cancer patients and is recommended as a promising therapeutic alternative. 相似文献
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PD Guinan JP Imperato JS Chmiel NJ Vogelzang J Sylvester 《Canadian Metallurgical Quarterly》1997,5(5):305-308
In a previous study, we showed that overexpression of cyclin D, a G1 cyclin, is frequently associated with keratinocyte carcinogenesis as an early event. Another G1 cyclin, cyclin E, was recently suggested to be a prognostic marker for breast cancer. In order to evaluate the role of cyclin E in human keratinocyte carcinogenesis, we analysed the expression of cyclin E by immunohistochemistry in normal skin, seborrheic keratosis (SK), keratoacanthoma (KA), actinic keratosis (AK), Bowen's disease (BD), basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Positive cells were seen rarely in normal epidermis, in 9 of 20 cases of SK, in 5 of 6 cases of KA, in 9 of 13 cases of AK and in all 27 cases of BD. Some of the cases of AK and BD had positive cells in the superficial epidermis, where atypicality is less obvious. In contrast, positive cells were seen in 4 of 25 cases of SCC and none of 15 cases of BCC. These results suggest that expression of cyclin E plays a role in the formation of benign and premalignant keratinocytic tumors, whereas down-regulation of cyclin E expression may be involved in carcinogenesis in human keratinocytes. 相似文献