Intra-Abdominal Desmoplastic Small Round Cell Tumor

We report a case of malignant intraabdominal tumor in a 14 years old Korean girl that presented with abdominal pain, distension and palpable mass. Emergency laparotomy revealed bulky peritoneal masses with numerous satellite implanting nodules. Ught microscopically the tumor was characterized by discrete islands of compact, small epithelium-like cells encased in desmoplastic stroma. Immunohistochemically the neoplastic cells expressed vimentin strongly and diffusely and also neuron specific enolase strongly and focally. Ultrastructurally the neoplastic cells showed whorled intermediate filaments, a fair number of mitochondria, dilated rough endoplasmic reticulum, a few fat vacuoles and zonula-adherens type junctions. However there was no evidence of specific differentiation. Histologic, immunohistochemical, and electronmicroscopic observations indicated a primitive malignant neoplasm simultaneously expressing mesenchymal and neural differentiation. Our case did not express any epithelial markers including pancytokeratin, epithelial membrane antigen and CAM 5.2

Electroluminescence in polymer-fullerene photovoltaic cells

We report electroluminescence (EL) in photovoltaic (PV) cells based on semiconducting polymer-fullerene composites. By applying a forward bias to the PV cells, the devices exhibited a clear EL action with a peak around 1.5 eV. We ascribe this peak to an "electric field-assisted exciplex" formed between the electrons in the fullerenes and the holes in the polymers, thereby resulting in radiative recombination in the composites. This finding is totally unexpected because of a strong photoluminescence quenching in the same materials. Since the same devices also showed typical photovoltaic effects under illumination, our results demonstrate a dual functionality in one device; polymer photovoltaic cells and polymer light-emitting diodes.open464

Semiconducting Polymer Photodetectors with Electron and Hole Blocking Layers: High Detectivity in the Near-Infrared

Sensing from the ultraviolet-visible to the infrared is critical for a variety of industrial and scientific applications. Photodetectors with broad spectral response, from 300 nm to 1,100 nm, were fabricated using a narrow-band gap semiconducting polymer blended with a fullerene derivative. By using both an electron-blocking layer and a hole-blocking layer, the polymer photodetectors, operating at room temperature, exhibited calculated detectivities greater than 1013 cm Hz1/2/W over entire spectral range with linear dynamic range approximately 130 dB. The performance is comparable to or even better than Si photodetectors

Isomeric iminofullerenes as acceptors in bulk heterojunction organic solar cells

Two stable iminofullerene isomers, [5,6]-open azafulleroid (open APCBM) and [6,6]-closed aziridinofullerene (closed APCBM) enable us to scrutinize the use of these new acceptors in polymer bulk heterojunction (BHJ) solar cells and compare the effects of open trans- and closed trans-annlar subunits. When we compared the performance of both isomer devices, the poly(3-hexylthiophene)(P3HT):open APCBM device demonstrates an enhancement in photocurrent in comparison with the P3HT: closed APCBM device. From the comparative study, we attribute the enhanced current to the lower degree of symmetry of open APCBM. The alteration of fullerene structure from closed to open breaks its high degree of symmetry and consequently leads to an improved bulk heterojunction with the electron donating conjugated polymer.close242

Early Bile Duct Cancer Detected by Direct Peroral Cholangioscopy with Narrow-Band Imaging after Bile Duct Stone Removal

Cholangioscopy not only enables the direct visualization of the biliary tree, but also allows for forceps biopsy to diagnosis early cholangiocarcinoma. Recently, some reports have suggested the clinical usefulness of direct peroral cholangioscopy (POC) using an ultra-slim endoscope with a standard endoscopic unit by a single operator. Enhanced endoscopy, such as narrow band imaging (NBI), can be helpful for detecting early neoplasia in the gastrointestinal tract and is easily applicable during direct POC. A 63-year-old woman with acute cholangitis had persistent bile duct dilation on the left hepatic duct after common bile duct stone removal and clinical improvement. We performed direct POC with NBI using an ultra-slim upper endoscope to examine the strictured segment. NBI examination showed an irregular surface and polypoid structure with tumor vessels. Target biopsy under direct endoscopic visualization was performed, and adenocarcinoma was documented. The patient underwent an extended left hepatectomy, and the resected specimen showed early bile duct cancer confined to the ductal mucosa

Synergistic surface modification for high-efficiency perovskite nanocrystal light-emitting diodes: divalent metal ion doping and halide-based ligand passivation

Surface defects of metal halide perovskite nanocrystals (PNCs) substantially compromise the optoelectronic performances of the materials and devices via undesired charge recombination. However, those defects, mainly the vacancies, are structurally entangled with each other in the PNC lattice, necessitating a delicately designed strategy for effective passivation. Here, a synergistic metal ion doping and surface ligand exchange strategy is proposed to passivate the surface defects of CsPbBr3 PNCs with various divalent metal (e.g., Cd2+, Zn2+, and Hg2+) acetate salts and didodecyldimethylammonium (DDA+) via one-step post-treatment. The addition of metal acetate salts to PNCs is demonstrated to suppress the defect formation energy effectively via the ab initio calculations. The developed PNCs not only have near-unity photoluminescence quantum yield and excellent stability but also show luminance of 1175 cd m−2, current efficiency of 65.48 cd A−1, external quantum efficiency of 20.79%, wavelength of 514 nm in optimized PNC light-emitting diodes with Cd2+ passivator and DDA ligand. The “organic–inorganic” hybrid engineering approach is completely general and can be straightforwardly applied to any combination of quaternary ammonium ligands and source of metal, which will be useful in PNC-based optoelectronic devices such as solar cells, photodetectors, and transistors