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Immunological treatment of malignant human tumors has so far met with little success. Based on methods and insights obtained by investigation of corresponding animal models, this article attempts to elucidate the reasons for this failure and to suggest ways and means to improve immunotherapeutic approaches to human neoplasms.  相似文献   
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复合垂直流湿地反应动力学及水流流态的研究   总被引:17,自引:2,他引:17       下载免费PDF全文
 提出一种新型的复合垂直流湿地系统(IVCW),并对其反应动力学和系统的实际流态进行了研究.经过中试的运行试验,得到了系统对COD去除的反应速率方程,由示踪剂试验确定了系统中水流的停留时间分布(RTD),提出RTD的不同是湿地处理效率差异的主要原因,进而运用串联反应器模型和离散流模型两种非理想流态模型,模拟IVCW的实际水流流态,经过比较发现离散流模型模拟的效果较好.  相似文献   
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The consequences of exposure of people to highly chlorinated polychlorodibenzo-p-dioxins (PCDDs) are much less known than those of TCDD. We report on levels of PCDDs (and PCDFs) in 13 members of two families poisoned by contaminated cooking oil. Originally, all persons displayed chloracne as an early symptom. Persisting hexa- and higher chlorinated PCDDs could be analysed many years after exposure. Highest values found in blood lipids were: OCDD 660,000 pg/g; HpCDD 58,000 pg/g; HxCDDs: 3500 pg/g. None of the participants exhibited increased TCDD levels at the time of study. During a period of 6 years, HpCDD and OCDD disappeared from the blood lipids much faster in persons exposed as children or young adults, than from lipids of their parents. Surface receptors on blood lymphocytes of the members of the two families and the proliferative capacity of these blood cells in the presence of typical stimulants were analysed. Even in family members with the highest body burdens of hexa- to octachlorinated PCDDs we could not detect pronounced changes from a reference population with respect to the immunological markers. Minor deviations of levels of some receptors in a few, but not all, highly exposed persons suggested a similar trend to those reported in previous studies of persons with body burdens of > or =3000 pg TCDD/g blood lipids. An increase in the number of total blood lymphocytes in some subjects exposed as children may have similarity with highly TCDD-exposed children in Seveso.  相似文献   
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This study assesses the direct and indirect environmental impacts to be expected if Switzerland should replace one percent of its current diesel consumption with imports of A) soybean methyl ester (SME) from Brazil, or B) palm methyl ester (PME) from Malaysia. In order to take into account possible future consequences, what-if scenarios were developed and assessed by means of a consequential LCA. In contrast to attributional LCA, the consequential approach uses system enlargement to include the marginal products affected by a change of the physical flows in the central life cycle. This means that the LCA considers all inputs and outputs which are linked to biodiesel production and that the product system is subsequently expanded to include the marginal products affected. Both future systems are assessed in comparison with the environmental scores of the fossil equivalent to biodiesel, i.e. diesel low in sulphur. The environmental burdens are measured by means of greenhouse gas emissions (GHG), land occupation and various non-aggregated and aggregated environmental impact indicators.In sum, the environmental impacts of an increased SME consumption depend on the environmental scores of the marginal replacement products on the world market, rather than on local production factors. In other words, the marginal products assumed to be affected are most important for the results obtained, i.e. in particular the marginal vegetable oil, fodder cake and land areas. In this study it is SME production increased at the expense of the available soybean oil which shifts the impacts associated with soybean oil production to the production of the marginal vegetable oils on the world market. In this perspective, it is not relevant in which country biodiesel production takes place, but rather which vegetable oil is involved. With respect to PME, the most relevant determining factor for the environmental impacts is the land area affected by the increased cultivation of oil palms. Currently, this expansion displaces primarily peat land and rain forest. This causes GHG emissions which are much higher than the emissions of the fossil reference. All in all, both PME from Malaysia and SME from Brazil cause more environmental impact than allowed by the Swiss tax redemption on agro-biofuels (max. 60% GHG emissions and 125% UBP of the fossil reference).  相似文献   
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