Using a molten organic conducting material to infiltrate a nanoporous semiconductor film and its use in solid-state dye-sensitized solar cells

We describe a method to fill thin films of nanoporous TiO₂ with solid organic hole-conducting materials and demonstrate the procedure specifically for use in the preparation of dye-sensitized solar cells. Cross-sections of the films were investigated by scanning electron microscopy and it was observed that a hot molten organic material fills pores that are 10 μm below the surface of the film. We characterized the incident photon to current conversion efficiency properties of the solid TiO₂/organic dye/organic hole-conductor heterojunctions and the spectra show that the dye is still active after the melting process.     

Pancreatic cancer and comparison of a hospital-based tumor registry with a National Cancer Data Base

BACKGROUND: The Commission on Cancer of the American College of Surgeons has called upon institutions providing cancer care to compare practice patterns and outcomes with the National Cancer Data Base (NCDB). Using data from the Virginia Mason Tumor Registry (VMTR), we sought to compare our pancreatic cancer care patterns with those reported nationally, while critically evaluating the accuracy and usefulness of our registry. METHODS: A review of the 906 computerized patient files in the VMTR from 1973 to 1995 was performed, with more detailed data on patients from the last 5 years retrieved from 224 manual abstracts. These data were compared with the 1991 NCDB for pancreatic cancer. RESULTS: The percent of cases according to AJCC stage in the NCDB (n = 9,715) versus the VMTR (n = 149), respectively, with cases of unknown stage excluded, were stage I 22% versus 22%, stage II 9% versus 12%, stage III 17% versus 28% (P <0.05) stage IV 52% versus 38% (P <0.05). One-third of the cases in the VMTR 1991 to 1995 were of unknown stage; number of cases with unknown stage for NCDB was 26.6%. The percent of surgical procedures for the NCDB (n = 7,802) versus the VMTR (n = 224), respectively, was pancreatectomy 14% versus 11%, local excision 1% versus 0%, no cancer-directed surgery 83% versus 89% (P <0.05), unknown 2% versus 0% (P <0.05). The actuarial relative survival rates for the 1991 NCDB versus 1987 to 1995 VMTR was 3-year 18% versus 38%, and 5-year 14% versus 35%. CONCLUSIONS: In comparison with the NCDB, VMTR may have fewer stage IV pancreatic cancers, but improvement is needed in decreasing the number of patients for whom the stage is unknown, as many of these likely represent late stage disease. We have a similar resection rate and a higher survival compared with the NCDB, but a mechanism is not in place to statistically compare our survival data with those of the NCDB. Even though all accredited hospitals are required to have a tumor registry, our data were difficult to compare with those of the NCDB because of coding and reporting deficiencies and inability to statistically compare survival data. Before our practice patterns and outcomes can be compared with national standards, both the VMTR and the NCDB must have standardized data collection and better access to the data.     

Risk factors and outcome of human immunodeficiency virus-infected patients with sporadic multidrug-resistant tuberculosis in New York City

The discovery of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma has opened a potentially new therapeutic approach in this group of patients with a poor prognosis and few effective therapy modalities. Based on previous findings of increased uptake of 11C-5-hydroxytryptophan (11C-5-HTP) in neuroendocrine tumours using the PET technique, this tracer was applied in the study of 10 patients with metastatic hormone-refractory prostatic adenocarcinoma. In three patients, the study was repeated after treatment. An increased uptake of 11C-5-HTP was observed in all investigated skeletal lesions, although the magnitude of the uptake was moderate. The difference between the standard uptake values (SUV) in normal bone and metastatic lesions was significant (p < 0.001). A kinetic analysis of the uptake of 11C-5-HTP demonstrates an increase during the first minutes followed by a wash-out and a stabilization of the tissue/blood ratio at about 2. The Patlak plots demonstrated a gradual increase in the transport rate during the first 20 to 30 min, after which a constant level was observed. The SUV varied between patients and between lesions over time and treatment. The uptake of 11C-5-HTP discriminates metastatic lesions from normal bone and may thus aid in the diagnosis and, potentially, in treatment monitoring of metastatic hormone-refractory prostatic adenocarcinoma. Uptake kinetics are characterized by a wash-out and cannot alone be used as proof of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma.