Nitrogen doping into titanium dioxide by the sol–gel method using nitric acid

N-doped TiO(2) has been prepared by use of sol-gel systems containing titanium alkoxide, with nitric acid as the nitrogen source. The time needed for gelation of the systems was drastically reduced by ultrasonic irradiation. The peaks assigned to the nitrate and nitrous ions were observed by FT-IR measurement during the sol-gel reaction. The N-doping was confirmed by the observation of N-O peaks in the XPS spectrum of the sample heated at 400 A degrees C. The nitrate ion acted as an oxidizer of the ethanol solvent and titanium species. The TiO(2) became doped with nitrogen oxide species as a result of reduction of nitrate ion incorporated into the dried gel samples. These results indicated that the added nitric acid was reduced during the sol-gel transition and heating process, and the resulting NO species were situated in the titania networks. The UV and visible photocatalytic activity of the samples was confirmed by the degradation of trichloroethylene.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 37(8):869-881 (2011)journal articl

Photomechanical Energy Conversion of Photoresponsive Fibers Exhibiting Bending Behavior

Photoresponsive fibers based on poly(acrylamide) (PAA) with methylene blue (MB) dye were prepared. All semicircular fibers show bending towards the direction of the flat surface of the fiber when illuminated. The fibers recover their initial shape when the illumination stops. The fiber is heated upon illumination and cooled to room temperature once the illumination is stopped. The fiber also is sensitive to humidity, showing bending behavior towards the direction of the flat surface of the fiber upon changing the humidity. The mechanical energy of the PAA/MB fiber is approximately 0.6 mN for the bending direction when it is illuminated. A possible mechanism for the bending behavior is as follow: (1) the fiber is heated upon illumination because of the photothermal effect, (2) the fiber loses water molecules, (3) the fiber shrinks; bending towards the direction of the flat surface of the fiber occurs because of a difference in the shrinkage for the flat surface and the other side of the fiber. Finally, we demonstrated that a PP ball (1.5 mg) can be moved by the mechanical energy produced by the changing shape of the fiber upon illumination

Two cases of pelvic hematoma after prostatic urethral lift surgery

Introduction There are few reports of pelvic hematoma after prostatic urethral lift. Here, we report two cases of pelvic hematoma in Japan. Case presentation The first case was a 71‐year‐old man with benign prostatic hyperplasia who underwent prostatic urethral lift. Although the procedure was uneventful, he experienced lower abdominal pain the day after the operation. CT revealed a hematoma in the right pelvis; however, it was manageable with conservative treatment. The second case was a 68‐year‐old man. The procedure was uneventful; however, 6 days after the operation, a subcutaneous hematoma appeared in the lower abdomen. CT revealed a hematoma in the left pelvis. We then performed pelvic hematoma removal surgery. Conclusions Pelvic hematomas after PUL may requires attention, particularly in men with the narrow pelvises. Appropriate compression of the prostate and a high lithotomy position procedure could effectively avoid the occurrence of pelvic hematomas

Role of Four-Fold Coordinated Titanium and Quantum Confinement in CO2 Reduction at Titania Surface

Photocatalytic reduction of carbon dioxide (CO2) into hydrocarbons is an attractive approach for mitigating CO2 emission and generating useful fuels at the same time. Titania (TiO2) is one of the most promising photocatalysts for this purpose, and nanostructured TiO2 materials often lead to an increased efficiency for the photocatalytic reactions. However, what aspects of and how such nanomaterials play the important role in the improved efficiency are yet to be understood. Using first-principles calculations, reaction mechanisms on the surface of bulk anatase TiO2(101) and of a small TiO2 nanocluster were investigated to elucidate the role of four-fold coordinated titanium atoms and quantum confinement (QC) in the CO2 reduction. Significant barrier reduction observed on the nanocluster surface is discussed in terms of how the under-coordinated titanium atoms and QC influence CO2 reduction kinetics at surface. It is shown that the reduction to CO can be greatly facilitated by the under-coordinated titanium atoms, and they also make CO2 anion formation favorable at surfaces.11Nsciescopu