The development of drugs for the control of tumor angiogenesis requires a simple, accurate, and economical assay for tumorinduced vascularization. We have adapted the orthotopic implantation model to angiogenesis measurement by using human tumors labeled with Aequorea victoria green fluorescent protein for grafting into nude mice. The nonluminous induced capillaries are clearly visible against the very bright tumor fluorescence examined either intravitally or by whole-body luminance in real time. The orthotopic implantation model of human cancer has been well characterized, and fluorescence shadowing replaces the laborious histological techniques for determining blood vessel density. Intravital images of orthotopically implanted human pancreatic tumors clearly show angiogenic capillaries at both primary and metastatic sites. A quantitative time course of angiogenesis was determined for an orthotopically growing human prostate tumor periodically imaged intravitally in a single nude mouse over a 19-day period. Whole-body optical imaging of tumor angiogenesis was demonstrated by injecting fluorescent Lewis lung carcinoma cells into the s.c. site of the footpad of nude mice. The footpad is relatively transparent, with comparatively few resident blood vessels, allowing quantitative imaging of tumor angiogenesis in the intact animal. Capillary density increased linearly over a 10-day period as determined by whole-body imaging. Similarly, the green fluorescent protein-expressing human breast tumor MDA-MB-435 was orthotopically transplanted to the mouse fat pad, where whole-body optical imaging showed that blood vessel density increased linearly over a 20-week period. These powerful and clinically relevant angiogenesis mouse models can be used for real-time in vivo evaluation of agents inhibiting or promoting tumor angiogenesis in physiological microenvironments.green fluorescent protein ͉ metastatic models ͉ external optical imaging T umor vascularization or angiogenesis is a critical step in tumor growth, progression, and metastasis. As such, angiogenesis promises a uniquely effective yet remarkably benign target for cancer chemotherapy. A major requirement for the effective discovery of angiogenesis-related drugs is an assay system that is accurate, rapid, and economical. We report a model system that meets these requirements.The discovery and evaluation of antiangiogenic substances initially relied on in vivo methods such as the chorioallantoic membrane assay (1, 2), the monkey iris neovascularization model (3), the disk angiogenesis assay (4), and various models that use the cornea to assess blood vessel growth (5-10). Although they are important for understanding the mechanisms of blood vessel induction, these models did not deal with tumor angiogenesis and are poorly suited to drug discovery.Subcutaneous tumor xenograft angiogenesis models have been developed to study tumor angiogenesis, but these require cumbersome pathological examination procedures such as histology and immunohistochemistry. Measurements requi...

Melt holding time has important influences on the modification effect of Sr modified AS31 alloy. Effects of different melt holding time (30min, 60min, 90min and 120min) at 700°C on as cast microstructure and tensile properties both at ambient temperature and elevated temperature of Sr-modified AS31 alloy were studied. There exist polyhedral shape, fine fibers shape and a few Chinese script Mg2Si particles in Sr-modified AS31 alloys. And the average grain size is smallest in Sr-modified AS31 alloys with holding time at 700°C for 30min. The ultimate strength, yield strength and elongation at both ambient temperature and 150°C decrease gradually when the melt holding time increases from 30min to 120min. In the process of smelting of Sr-modified AS31. The burning loss of Sr element becomes more serious with the prolongation of melt holding time, which contributes to the modification effect reducing.

A356 alloy was refined with a new master alloy of Al-5Ti-B-10Sr. The microstructure and mechanical properties of the refined A356 alloy with different content of master alloy (0, 0.1, 0.3, 0.5 and 0.7 wt.%) were investigated. The results show that the refining effect becomes stronger as the master alloy content increasing from 0.1 to 0.3 wt.%, and then shows slight decrement until 0.7 wt.%. An optimal combination of the tensile strength (193 MPa) and the elongation (17.8%) of as-cast A356 alloy was achieved with 0.3 wt.% of refining master alloy. Compared to the non-modified A356 alloy, the tensile strength and the elongation were improved by 10% and 242%, respectively.

Effects of different species of Sr additives (pure Sr, cast Mg-10Sr block, Ф10mm extruded Al-10Sr bar) on as-cast microstructure and tensile properties both at ambient temperature and elevated temperature of AS31 alloy were studied. The experimental results showed that pure Sr, Mg-10Sr, Al-10Sr additions all could refine the grains of AS31 alloy obviously, modify the eutectic Mg2Si particles and strengthen AS31 alloy. Al-10Sr is most effective to refine microstructure and improve mechanical properties of AS31 alloy.