Physica Meletemata Disputationibus Viginti Et Quinque Comprehensa

PHYSICA MELETEMATA DISPUTATIONIBUS VIGINTI ET QUINQUE COMPREHENSA Physica Meletemata Disputationibus Viginti Et Quinque Comprehensa De Natura Physicae (1) De Principiis Demonstrativis Physicae (2) De Materia (3) De Materia (4) De Forma (5) De Efficiente Et Fine (6) De Corpore Naturali, Et Affectionibus Eius In Genere (8) De Quantitate Et Qualitate (9) De Generatione (17) De Temperamento (18

Systemic application of photosensitizers in the chick chorioallantoic membrane (CAM) model: photodynamic response of CAM vessels and 5-aminolevulinic acid uptake kinetics by transplantable tumors

The aim of this study is to modify the chick chorioallantoic membrane (CAM) model into a whole-animal tumor model for photodynamic therapy (PDT). By using intraperitoneal (i.p.) photosensitizer injection of the chick embryo, use of the CAM for PDT has been extended to include systemic delivery as well as topical application of photosensitizers. The model has been tested for its capability to mimic an animal tumor model and to serve for PDT studies by measuring drug fluorescence and PDT-induced effects. Three second-generation photosensitizers have been tested for their ability to produce photodynamic response in the chick embryo/CAM system when delivered by i.p. injection: 5-aminolevulinic acid (ALA), benzoporphyrin derivative monoacid ring A (BPD-MA), and Lutetium-texaphyrin (Lu-Tex). Exposure of the CAM vasculature to the appropriate laser light results in light-dose-dependent vascular damage with all three compounds. Localization of ALA following i.p. injections in embryos, whose CAMs have been implanted with rat ovarian cancer cells to produce nodules, is determined in real time by fluorescence of the photoactive metabolite protoporphyrin IX (PpIX). Dose-dependent fluorescence in the normal CAM vasculature and the tumor implants confirms the uptake of ALA from the peritoneum, systemic circulation of the drug, and its conversion to PpIX

Nitrogen deposition and climate change has increased vascular plant species richness and altered the composition of grazed subalpine grasslands

1-Atmospheric nitrogen (N) deposition and climate warming are two major components of global change that drive species richness and composition in plant communities. However, their combined effects have been insufficiently investigated across large spatial and temporal scales particularly in high-elevation, nutrient-limited ecosystems.2-We examine whether and how N deposition and climate warming have altered the plant richness and the composition of subalpine semi-natural, extensively grazed grasslands of the Pyrenees, using two complementary approaches: i) analysis of 553 relevés to explore vegetation changes across large ecological gradients including temperature and N deposition (spatial approach) and ii) a resampling of a subset of 40 sites among the 553 sites to assess temporal changes over the past decades (temporal approach).3-Both approaches showed that the vascular plant species richness increased when temperature and cumulative N deposition increase, shifting of the species composition toward more thermophilic and eutrophic communities.4-Synthesis. We hypothesize that the release from abiotic constraints (milder temperature and higher N availability) due to global changes and long-standing extensive grazing counteracting the negative effects of N deposition have been responsible for the diversity and compositional changes of plant communities over the last decades in the Pyrenees. Thus, in contrast with other grasslands, high-elevation grazed grasslands may increase in species diversity with N deposition under climate warming