First insights into the molecular basis of pleomorphic adenomas of the salivary glands.

Pleomorphic adenoma, or mixed tumor of the salivary glands, is a benign tumor originating from the major and minor salivary glands. Eighty-five percent of these tumors are found in the parotid gland, 10% in the minor (sublingual) salivary glands, and 5% in the submandibular gland. It is the most common type of salivary gland tumor, accounting for almost 50% of all neoplasms in these organs. In fact, after the first observation of recurrent loss of chromosome 22 in meningioma, this was the second type of benign tumor for which non-random chromosomal changes were reported. The rate of malignant change with the potential to metastasize has been reported to be only 2 to 3%, and only a few cases of metastasizing pleomorphic salivary gland adenomas have been described to date. The fact that these tumors arise in organs located in an ontogenetic transitional zone, a region where endoderm and ectoderm meet, might be one of the reasons for the often-problematic histopathological classification. This type of benign tumor has been cytogenetically very well-characterized, with several hundreds of tumors karyotyped. In addition to the cytogenetic subgroup with an apparently normal diploid stemline (making up approximately 30% of the cases), three major cytogenetic subgroups can be distinguished. In addition to a subgroup showing non-recurrent clonal abnormalities, another subgroup is various translocations involving 12q15. By far the largest cytogenetic subgroup, however, consists of tumors with chromosome 8 abnormalities, mainly showing translocations involving region 8q12. The most frequently encountered aberration in this group is a t(3;8)(p21;q12)

Ephocell project: smart light collecting system for the efficiency enhancement of solar cells - ray trace modeling of system

PV cell efficiency is limited partly due to the spectral mismatch between the solar spectrum and the PV absorption properties. PV conversion efficiency is enhanced by external modulation of the incident irradiance, by means of photon downshifting (DS) and upconversion (UC). A ray-trace modelling tool is presented to simulate the luminescent DS and UC processes and thereby optimise the doping concentrations and geometric dimensions of the DS and UC layers.Peer ReviewedPostprint (published version

Ephocell project: smart light collecting system for the efficiency enhancement of solar cells - ray trace modeling of system

PV cell efficiency is limited partly due to the spectral mismatch between the solar spectrum and the PV absorption properties. PV conversion efficiency is enhanced by external modulation of the incident irradiance, by means of photon downshifting (DS) and upconversion (UC). A ray-trace modelling tool is presented to simulate the luminescent DS and UC processes and thereby optimise the doping concentrations and geometric dimensions of the DS and UC layers.Peer Reviewe

Ephocell project: smart light collecting system for the efficiency enhancement of solar cells - ray trace modeling of system

PV cell efficiency is limited partly due to the spectral mismatch between the solar spectrum and the PV absorption properties. PV conversion efficiency is enhanced by external modulation of the incident irradiance, by means of photon downshifting (DS) and upconversion (UC). A ray-trace modelling tool is presented to simulate the luminescent DS and UC processes and thereby optimise the doping concentrations and geometric dimensions of the DS and UC layers.Peer Reviewe