Groove-Assisted Global Spontaneous Alignment of Carbon Nanotubes in Vacuum Filtration.

Ever since the discovery of carbon nanotubes (CNTs), it has long been a challenging goal to create macroscopically ordered assemblies, or crystals, of CNTs that preserve the one-dimensional quantum properties of individual CNTs on a macroscopic scale. Recently, a simple and well-controlled method was reported for producing wafer-scale crystalline films of highly aligned and densely packed CNTs through spontaneous global alignment that occurs during vacuum filtration (Nat. Nanotechnol. 2016, 11, 633). However, a full understanding of the mechanism of such global alignment has not been achieved. Here, we report results of a series of systematic experiments that demonstrate that the CNT alignment direction can be controlled by the surface morphology of the filter membrane used in the vacuum filtration process. More specifically, we found that the direction of parallel grooves pre-existing on the surface of the filter membrane dictates the direction of the resulting CNT alignment. Furthermore, we intentionally imprinted periodically spaced parallel grooves on a filter membrane using a diffraction grating, which successfully defined the direction of the global alignment of CNTs in a precise and reproducible manner. These results are promising not only for developing novel devices based on macroscopically aligned CNTs but also for understanding the microscopic physical mechanism of the alignment process.

A pH sensor based on electric properties of nanotubes on a glass substrate.

We fabricated a pH-sensitive device on a glass substrate based on properties of carbon nanotubes. Nanotubes were immobilized specifically on chemically modified areas on a substrate followed by deposition of metallic source and drain electrodes on the area. Some nanotubes connected the source and drain electrodes. A top gate electrode was fabricated on an insulating layer of silane coupling agent on the nanotube. The device showed properties of ann-type field effect transistor when a potential was applied to the nanotube from the top gate electrode. Before fabrication of the insulating layer, the device showed that thep-type field effect transistor and the current through the source and drain electrodes depend on the buffer pH. The current increases with decreasing pH of the CNT solution. This device, which can detect pH, is applicable for use as a biosensor through modification of the CNT surface.

Concurrent chemoradiotherapy for locally advanced and metastatic esophageal cancer: longterm results of a phase II study of UFT/CDDP with radiotherapy.

BACKGROUND: No effective treatment for advanced esophageal cancer extending to adjacent organs or associated with distant metastasis is known. We prospectively analyzed the efficacy of concurrent chemoradiotherapy with uracil plus tegafur (UFT) and cisplatin (CDDP) for such cases of advanced esophageal cancer. METHODS: Patients with advanced cancers received 60 to 70 Gy of radiotherapy given during a period of 7 weeks, concurrently with daily oral UFT (200 mg/m(2) per day), and a 24-h infusion of CDDP (70 mg/m(2)) on days 8 and 36. After chemoradiotherapy, UFT (250 mg/m(2)/per day) was administered daily for 1 year, while CDDP (80 mg/m(2)) was administered twice every 4 weeks. RESULTS: Patients with stage III disease numbered 31, while 24 had stage IV disease according to the tumor-node-metastasis (TNM) staging. Including all patients, complete response (CR) occurred in 20% and partial response (PR) in 51%. In stage III patients, CR, PR, and CR+PR rates were 29%, 48%, and 77%, respectively. In stage IV patients, CR, PR, and CR+PR rates were 8%, 54%, and 63%. Grade 4 leukocytopenia occurred in 22% of patients, and grade 3 pain, nausea/vomiting, and oral mucositis occurred in 7%, 9%, and 4% of patients respectively, but resolved after the reduction or discontinuation of chemoradiotherapy. Median survival in stage III patients was 415 days (range, 3 to 3046 days), and in stage IV patients, it was 187 days (range, 75 to 764 days). The 2-year survival rate in stage III patients was 25% and it was 4% in stage IV patients. The 5-year survival rate in stage III patients was 7%, while in stage IV patients it was 0%. CONCLUSION: This combined treatment may be a promising nonsurgical management option for locally advanced esophageal cancer, and can achieve good palliative effects in patients with distant metastasis.