Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased ac...Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased accuracy and precision in the delivery of dose.While these developments are well established since a fairly long time for external beam radiotherapy,they are yet to be firmly established in many brachytherapy units all over the world particularly in the developing countries.We will review the basic principles of image-based brachytherapy and explore the potential clinical opportunities behind this innovative technique.展开更多
In his commentary on the Platonic Parmenides, the Neoplatonist philosopher Proclus （ca. 411-485） offers a systematic defense of the objective existence of the Forms by means of the use of distinctive arguments, four...In his commentary on the Platonic Parmenides, the Neoplatonist philosopher Proclus （ca. 411-485） offers a systematic defense of the objective existence of the Forms by means of the use of distinctive arguments, four of which are ontological. In contrast with Aristotle, Proclus clearly accepts that the Forms exist as principles of the world and not as posterior concepts describing the common elements of the sensible entities. Thus, he argues first that the ontological presuppositions of the sensible beings are placed in the area of the self-subsistent beings, which correspond to the categories of the Second Hypothesis of the Parmenides. The Forms belong to this area as well. In this respect, Proclus refers to the way of production of the sensible beings, aiming at a strict definition of this process. Secondly, he proves that the existence of the Forms, which possess ontological completeness, is prior to the existence of the sensible things. This is possible since the Forms are generated by the Demiurge of the whole world, by means of an internal reflection upon himself. Thirdly, in order to prove that the sensible world cannot be attributed to mere chance, he argues that the external activity, i.e., the creation of the world, depends on the internal activity, i.e., the development of the Forms in the divine intellect. Fourthly, he implements the concept of hierarchy in the realm of the Forms, through an extensive reference to the ontological priority of the imparticipable over the participable. Thus, he shows how the existence of the primary and intelligible Forms is prior to that of the substantiated Forms. Interestingly enough, the above-mentioned arguments exercised considerable influence on the commentaries of the members of the school of Ammonius, son of Hermias.展开更多
文摘Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased accuracy and precision in the delivery of dose.While these developments are well established since a fairly long time for external beam radiotherapy,they are yet to be firmly established in many brachytherapy units all over the world particularly in the developing countries.We will review the basic principles of image-based brachytherapy and explore the potential clinical opportunities behind this innovative technique.
文摘In his commentary on the Platonic Parmenides, the Neoplatonist philosopher Proclus （ca. 411-485） offers a systematic defense of the objective existence of the Forms by means of the use of distinctive arguments, four of which are ontological. In contrast with Aristotle, Proclus clearly accepts that the Forms exist as principles of the world and not as posterior concepts describing the common elements of the sensible entities. Thus, he argues first that the ontological presuppositions of the sensible beings are placed in the area of the self-subsistent beings, which correspond to the categories of the Second Hypothesis of the Parmenides. The Forms belong to this area as well. In this respect, Proclus refers to the way of production of the sensible beings, aiming at a strict definition of this process. Secondly, he proves that the existence of the Forms, which possess ontological completeness, is prior to the existence of the sensible things. This is possible since the Forms are generated by the Demiurge of the whole world, by means of an internal reflection upon himself. Thirdly, in order to prove that the sensible world cannot be attributed to mere chance, he argues that the external activity, i.e., the creation of the world, depends on the internal activity, i.e., the development of the Forms in the divine intellect. Fourthly, he implements the concept of hierarchy in the realm of the Forms, through an extensive reference to the ontological priority of the imparticipable over the participable. Thus, he shows how the existence of the primary and intelligible Forms is prior to that of the substantiated Forms. Interestingly enough, the above-mentioned arguments exercised considerable influence on the commentaries of the members of the school of Ammonius, son of Hermias.
