The synthesis of some bromine-substituted rhodamine derivatives viz., 4,5-dibromorhodamine methyl ester (dye 2) and 4,5-dibromorhodamine n-butyl ester (dye 3) are reported. These dyes were synthesized to promote a more efficient cancer cell photosensitizer for potential use in in vitro bone marrow purging in preparation for autologous bone marrow transplantation. Spectroscopic and photophysical characterization of these dyes together with rhodamine 123 (dye 1) are reported in water, methanol, ethanol and also in a microheterogeneous system, sodium dodecyl sulfate. The possible mechanism of photosensitization is characterized in terms of singlet oxygen efficiency of these dyes. Singlet oxygen quantum yields for bromine-substituted dyes are in the range of 0.3-0.5 depending on the solvent. For dye 1 no singlet oxygen production is found. The photodynamic actions of these dyes in different cell lines are tested. It was found that dye 2 and dye 3 are efficient photosensitizers and mediate eradication of K562, EM2, myeloid cell lines (CML) and the SMF-AI rhabdomyosarcoma line.

The term "energy efficiency" has been widely used in global energy, economics, and environment, and it is well known that energy efficiency is one of the most cost-effective approaches in saving energy and mitigating greenhouse gas (GHG) emissions. However, it is still not clear how many metric tons of carbon dioxide (MTCO 2 ) can be mitigated if one dollar is invested in worldwide energy efficiency. This study tries to clear this issue. Using data of 49 completed energy efficiency projects funded by the Global Environment Facility (GEF), this study presents an analysis on investments of US$313 million in capacity building, asset acquisition, project development, and project implementation in 35 countries. Results show that every dollar invested by the GEF has mobilized 8.2 dollars in co-financing and can mitigate 1.89 MTCO 2 . In addition, GEF investments in capacity building, national policy, legal and regulatory frameworks have long term impact on GHG emission mitigations which is beyond quantification with current approaches. We conclude that public funds have greatly facilitated capacity building, catalyzed the transfer of environmentally sound technologies, and helped remove a large number of regulatory and market barriers to energy efficiency in developing countries and countries with economies in transition.

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