394 research outputs found
Jay\u27s Collectibles
There is growing interest in collectibles of many types, as indicated by the popularity of television programs such as the History Channel’s Pawn Stars and American Pickers and the Public Broadcasting Service’s Antiques Road Show. The availability of online auction sites such as eBay has enabled many people to collect items of interest as a hobby and to sell parts of their collection as a business or for extra income. As a collection grows, it becomes increasingly difficult to track through manual methods, and it is often useful to develop a computer-based system for this purpose. This case raises the possibility of developing an information system to manage a collection of sports autographs. This case may be used in a systems analysis and design, database, or systems development course to address a number of important topics such as: systems scope identification, problem and opportunity analysis, requirements analysis, data modeling, and application development. The case is designed to provoke interest and raise a sufficient level of complexity to challenge students to apply a range of systems development and database concepts. While the case addresses sports collectibles, its concepts may be applicable other types of systems, especially those involving other types of collections or “one of a kind” items. Since many students are likely to have at least some experience using online auction sites, following professional sports, seeing television programs about collectibles, or attending flea markets where collectibles are sold, the case builds in some way on their life experience. This teaching case enables students to discover how systems development and database concepts are applicable to a practical problem solving scenario
The role of hole transport between dyes in solid-state dye-sensitized solar cells
In dye-sensitized solar cells (DSSCs)
photogenerated positive charges
are normally considered to be carried away from the dyes by a separate
phase of hole-transporting material (HTM). We show that there can
also be significant transport within the dye monolayer itself before
the hole reaches the HTM. We quantify the fraction of dye regeneration
in solid-state DSSCs that can be attributed to this process. By using
cyclic voltammetry and transient anisotropy spectroscopy, we demonstrate
that the rate of interdye hole transport is prevented both on micrometer
and nanometer length scales by reducing the dye loading on the TiO<sub>2</sub> surface. The dye regeneration yield is quantified for films
with high and low dye loadings (with and without hole percolation
in the dye monolayer) infiltrated with varying levels of HTM. Interdye
hole transport can account for >50% of the overall dye regeneration
with low HTM pore filling. This is reduced to about 5% when the infiltration
of the HTM in the pores is optimized in 2 μm thick films. Finally,
we use hole transport in the dye monolayer to characterize the spatial
distribution of the HTM phase in the pores of the dyed mesoporous
TiO<sub>2</sub>
Pennsylvania Folklife Vol. 22, No. 4
• Let\u27s Talk About Slate • Ephrata Cloister Wills • A Blacksmith\u27s Summerkich • Pennsylvania German Astronomy and Astrology VI: Astrological Philosophy • Stoneware from New Geneva and Greensboro, Pennsylvania • American Emigration Materials from Pfeddersheim • Folk Medicine - Home Remedies: Folk-Cultural Questionnaire No. 29https://digitalcommons.ursinus.edu/pafolklifemag/1053/thumbnail.jp
Endoscopic mucosal resection (EMR) versus endoscopic submucosal dissection (ESD) for resection of large distal non-pedunculated colorectal adenomas (MATILDA-trial): Rationale and design of a multicenter randomized clinical trial
Background: Endoscopic mucosal resection (EMR) is currently the most used technique for resection of large distal colorectal polyps. However, in large lesions EMR can often only be performed in a piecemeal fashion resulting in relatively low radical (R0)-resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD) is a newer procedure that is more difficult resulting in a longer procedural time, but is promising due to the high en-bloc resection rates and the very low recurrence rates. We aim to evaluate the (cost-)effectiveness of ESD against EMR on both short (i.e. 6 months) and long-term (i.e. 36 months). We hypothesize that in the short-run ESD is more time consuming resulting in higher healthcare costs, but is (cost-) effective on the long-term due to lower patients burden, a higher number of R0-resections and lower recurrence rates with less need for repeated procedures. Methods: This is a multicenter randomized clinical trial in patients with a non-pedunculated polyp larger than 20 mm in the rectum, sigmoid, or descending colon suspected to be an adenoma by means of endoscopic assessment. Primary endpoint is recurrence rate at follow-up colonoscopy at 6 months. Secondary endpoints are R0-resection rate, perceived burden and quality of life, healthcare resources utilization and costs, surgical referral rate, complication rate and recurrence rate at 36 months. Quality-adjusted-life-year (QALY) will be estimated taking an area under the curve approach and using EQ-5D-indexes. Healthcare costs will be calculated by multiplying used healthcare services with unit prices. The cost-effectiveness of ESD against EMR will be expressed as incremental cost-effectiveness ratios (ICER) showing additional costs per recurrence free patient and as ICER showing additional costs per QALY. Discussion: If this trial confirms ESD to be favorable on the long-term, the burden of extra colonoscopies and repeated procedures can be prevented for future patients. Trial registration:NCT02657044(Clinicaltrials.gov), registered January 8, 2016
High incidence of Epstein-Barr virus, cytomegalovirus and human herpesvirus 6 infections in children with cancer
BACKGROUND: A prospective single-center study was performed to study infection with lymphotropic herpesviruses (LH) Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6) in children with cancer. METHODS: The group of 186 children was examined for the presence of LH before, during and 2 months after the end of anticancer treatment. Serology of EBV and CMV was monitored in all children, serology of HHV-6 and DNA analysis of all three LH was monitored in 70 children. RESULTS: At the time of cancer diagnosis (pre-treatment), there was no difference between cancer patients and age-matched healthy controls in overall IgG seropositivity for EBV (68.8% vs. 72.0%; p = 0.47) and CMV (37.6% vs. 41.7%; p = 0.36). During anticancer therapy, primary or reactivated EBV and CMV infection was present in 65 (34.9%) and 66 (35.4%) of 186 patients, respectively, leading to increased overall post-treatment IgG seropositivity that was significantly different from controls for EBV (86.6% vs. 72.0%; p = 0.0004) and CMV (67.7% vs. 41.7%; p < 0.0001). Overall pre-treatment IgG seropositivity for HHV-6 was significantly lower in patients than in controls (80.6% vs. 91.3%; p = 0.0231) which may be in agreement with Greaves hypothesis of protective effect of common infections in infancy to cancer development. Primary or reactivated HHV-6 infection was present in 23 (32.9%) of 70 patients during anticancer therapy leading to post-treatment IgG seropositivity that was not significantly different from controls (94.3% vs. 91.3%; p = 0.58). The LH infection occurred independently from leukodepleted blood transfusions given. Combination of serology and DNA analysis in detection of symptomatic EBV or CMV infection was superior to serology alone. CONCLUSION: EBV, CMV and HHV-6 infections are frequently present during therapy of pediatric malignancy
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