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21.
Zusammenfassung Die Kathepsin D-Aktivität des kollagenolytischen Kathepsins und der Pz-Peptidase wurden während der Bildung des mittels s.c. Injektion von Terpentinol hervorgerufenen Granuloms bei Ratten verfolgt. Die Kathepsin D-Aktivität erreichte am 10. Tag ihren Höhepunkt, diejenige des kollagenolytischen Kathepsins und der Pz-Peptidase erst am 14. Tag. In dieser Phase ist die Kollagenkonzentration herabgesetzt, während sich eine ausgeprägte Resorption des Granuloms zeigt.  相似文献   
22.
Systematic efforts are underway to decipher the genetic changes associated with tumor initiation and progression. However, widespread clinical application of this information is hampered by an inability to identify critical genetic events across the spectrum of human tumors with adequate sensitivity and scalability. Here, we have adapted high-throughput genotyping to query 238 known oncogene mutations across 1,000 human tumor samples. This approach established robust mutation distributions spanning 17 cancer types. Of 17 oncogenes analyzed, we found 14 to be mutated at least once, and 298 (30%) samples carried at least one mutation. Moreover, we identified previously unrecognized oncogene mutations in several tumor types and observed an unexpectedly high number of co-occurring mutations. These results offer a new dimension in tumor genetics, where mutations involving multiple cancer genes may be interrogated simultaneously and in 'real time' to guide cancer classification and rational therapeutic intervention.  相似文献   
23.
针对矩阵数据降维或低秩逼近问题,提出了一种快速增量算法.假设矩阵数据存在双边分解,建立了两个相互耦合的特征子空间模型,因此增量算法由两个特征子空间的迭代更新构成.每一步迭代,新载入的矩阵数据沿着行(列)特征子空间进行正交分解,从而获得了行(列)协方差矩阵更紧致的表达.一旦该表达被建立,行(列)特征子空间的更新就可以通过解一个和矩阵数据的行(列)数相比更小规模的特征值问题来完成,算法的高效率得以实现.该算法被应用到人脸图像重构和人脸跟踪问题中,一系列实验表明了算法的有效性.  相似文献   
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Over the past five years evidence has mounted that long-duration (>2 s) gamma-ray bursts (GRBs)-the most luminous of all astronomical explosions-signal the collapse of massive stars in our Universe. This evidence was originally based on the probable association of one unusual GRB with a supernova, but now includes the association of GRBs with regions of massive star formation in distant galaxies, the appearance of supernova-like 'bumps' in the optical afterglow light curves of several bursts and lines of freshly synthesized elements in the spectra of a few X-ray afterglows. These observations support, but do not yet conclusively demonstrate, the idea that long-duration GRBs are associated with the deaths of massive stars, presumably arising from core collapse. Here we report evidence that a very energetic supernova (a hypernova) was temporally and spatially coincident with a GRB at redshift z = 0.1685. The timing of the supernova indicates that it exploded within a few days of the GRB, strongly suggesting that core-collapse events can give rise to GRBs, thereby favouring the 'collapsar' model.  相似文献   
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