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31.
人类胚胎的道德地位   总被引:1,自引:0,他引:1  
张春美 《伦理学研究》2007,(5):64-67,77
胚胎干细胞技术的发展带来了干细胞来源的伦理争论,提出了如何看待"胚胎道德地位"的问题。围绕这一问题,有三种观点,它们分别从生物性、理性功能以及人的潜能性来界定胚胎的道德地位。通过对三种观点的分析,本文强调坚持人的尊严原则,是推动新兴生物技术发展的核心和归宿。  相似文献   
32.
总结提高胰头癌手术切除率、手术技巧和治疗效果的经验。回顾性分析自2003年9月起收治的39例胰头癌病人的临床资料,术中采用解剖性探查、蚊式钳勾划技术,对36例病人全部一次性行胰十二指肠切除术(PD)。手术切除率92.31%,剥离出的癌灶侵犯血管壁的断缘组织中镜下见到癌细胞25.93%,淋巴结转移率47.22%;胰周神经节、丛侵犯率55.56%,并发症发生率25.00%。解剖性探查、蚊式钳勾划技术的应用显著提高胰十二指肠切除率。  相似文献   
33.
随着干细胞生物学研究的不断深入,成体干细胞被发现可以分化成组织来源与其无关的其他系统的细胞,即成体干细胞的可塑性.但是最近不断有学者对其提出质疑,认为可塑性可能是与"细胞融合"或成年组织中的"多潜能成年祖细胞"有关.面对可塑性上两种截然相反的观点,我们在热切关注其研究进展的同时,也引发了一连串的哲学思考.  相似文献   
34.
糖尿病学家在胰腺及胰岛细胞移植领域进行了不懈的探索。胰腺移植和胰岛细胞移植的两大制约因素是可供移植的胰腺来源少且诱发受体免疫排斥反应而需应用免疫抑制剂。胰岛细胞制备、纯化技术以及免疫隔离技术的应用在一定程度上克服了上述两大制约因素,人们期待胰岛干细胞技术及其相关的基因技术的深入将这一技术趋于完善。  相似文献   
35.
Deep Learning has already shown power in many application fields, and is accepted by more and more people as a better approach than the traditional machine learning models. In particular, the implementation of deep learning algorithms, especially Convolutional Neural Networks (CNN), brings huge benefits to the medical field, where a huge number of images are to be processed and analyzed. This paper aims to develop a deep learning model to address the blood cell classification problem, which is one of the most challenging problems in blood diagnosis. A CNN-based framework is built to automatically classify the blood cell images into subtypes of the cells. Experiments are conducted on a dataset of 13k images of blood cells with their subtypes, and the results show that our proposed model provide better results in terms of evaluation parameters.  相似文献   
36.
通过研究慢性HBV感染者前C区变异及T细胞免疫功能与疾病的相关性,评估前C(preC)区变异及T细胞免疫功能对于慢性乙型肝炎(chronichepatitisB,CHB)预后的影响。分别采用实时荧光法、突变特异PCRmsPCR法及微粒酶免疫分析法对150例HBV-DNA阳性的CHB及50例健康体检者进行血清HBV-DN...  相似文献   
37.
克服肿瘤干细胞耐药性的策略和思路   总被引:1,自引:1,他引:0  
肿瘤干细胞(cancersterncells,CSCs)是肿瘤细胞的祖细胞。已有的研究表明,肿瘤干细胞对多种化疗药物具有耐药性,是导致肿瘤治疗后复发的根源。研究针对肿瘤干细胞的治疗方法,克服肿瘤干细胞耐药性,将给肿瘤治疗模式带来全新的改变,有望彻底改善肿瘤患者的预后。  相似文献   
38.
Theories of learning have historically taken, as their starting point, the assumption that learning processes have universal applicability. This position has been argued on grounds of parsimony, but has received two significant challenges: first, from the observation that some kinds of learning, such as spatial learning, seem to obey different rules from others, and second, that some kinds of learning take place in processing modules that are separate from each other. These challenges arose in the behavioural literature but have since received considerable support from neurobiological studies, particularly single neuron studies of spatial learning, confirming that there are indeed separable (albeit highly intercommunicating) processing modules in the brain, which may not always interact (within or between themselves) according to classic associative principles. On the basis of these neurobiological data, reviewed here, it is argued that rather than assuming universality of associative rules, it is more parsimonious to assume sets of locally operating rules, each specialized for a particular domain. By this view, although almost all learning is associative in one way or another, the behavioural-level characterization of the rules governing learning may vary depending on which neural modules are involved in a given behaviour. Neurobiological studies, in tandem with behavioural studies, can help reveal the nature of these modules and the local rules by which they interact.  相似文献   
39.
The President’s Council on Bioethics has addressed the moral status of human preembryos in its reports on stem cell research and human therapeutic cloning. Although the Council has been criticized for being hand-picked to favor the right-to-life viewpoint concerning human preembryos, it has embraced the idea that the right-to-life position should be defended in secular terms. This is an important feature of the Council’s work, and it demonstrates a recognition of the need for genuine engagement between opposing sides in the debate over stem cell research. To promote this engagement, the Council has stated in secular terms several arguments for the personhood of human preembryos. This essay presents and critiques those arguments, and it concludes that they are unsuccessful. If the best arguments in support of the personhood of human preembryos have been presented by the Council, then there are no reasonable secular arguments in support of that view.  相似文献   
40.
The author, a member of the U.S.President's Council on Bioethics, discussesethical issues raised by human cloning, whetherfor purposes of bringing babies to birth or forresearch purposes. He first argues that everycloned human embryo is a new, distinct, andenduring organism, belonging to the speciesHomo sapiens, and directing its owndevelopment toward maturity. He then distinguishesbetween two types of capacities belonging toindividual organisms belonging to this species,an immediately exerciseable capacity and abasic natural capacity that develops over time. He argues that it is the second type ofcapacity that is the ground for full moralrespect, and that this capacity (and itsconcomitant degree of respect) belongs tocloned human embryos no less than to adulthuman beings. He then considers and rejectscounter-arguments to his position, includingthe suggestion that the capacity of embryos isequivalent to the capacity of somatic cells,that full human rights are afforded only tohuman organisms with functioning brains, thatthe possibility of twinning diminishes themoral status of embryos, that the fact thatpeople do not typically mourn the loss of earlyembryos implies that they have a diminishedmoral status, that the fact that earlyspontaneous abortions occur frequentlydiminishes the moral status of embryos, andthat his arguments depend upon a concept ofensoulment. He concludes that if the moralstatus of cloned human embryos is equivalent tothat of adults, then public policy should bebased upon this assumption.  相似文献   
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