Large-Scale 1T'-Phase Tungsten Disulfide Atomic Layers Grown by Gas-Source Chemical Vapor Deposition.

The control of crystal polymorphism and exploration of metastable, two-dimensional, 1T'-phase, transition-metal dichalcogenides (TMDs) have received considerable research attention. 1T'-phase TMDs are expected to offer various opportunities for the study of basic condensed matter physics and for its use in important applications, such as devices with topological states for quantum computing, low-resistance contact for semiconducting TMDs, energy storage devices, and as hydrogen evolution catalysts. However, due to the high energy difference and phase change barrier between 1T' and the more stable 2H-phase, there are few methods that can be used to obtain monolayer 1T'-phase TMDs. Here, we report on the chemical vapor deposition (CVD) growth of 1T'-phase WS2 atomic layers from gaseous precursors, i.e., H2S and WF6, with alkali metal assistance. The gaseous nature of the precursors, reducing properties of H2S, and presence of Na+, which acts as a countercation, provided an optimal environment for the growth of 1T'-phase WS2, resulting in the formation of high-quality submillimeter-sized crystals. The crystal structure was characterized by atomic-resolution scanning transmission electron microscopy, and the zigzag chain structure of W atoms, which is characteristic of the 1T' structure, was clearly observed. Furthermore, the grown 1T'-phase WS2 showed superconductivity with the transition temperature in the 2.8-3.4 K range and large upper critical field anisotropy. Thus, alkali metal assisted gas-source CVD growth is useful for realizing large-scale, high-quality, phase-engineered TMD atomic layers via a bottom-up synthesis.

Gas Barrier Properties of Chemical Vapor-Deposited Graphene to Oxygen Imparted with Sub-electronvolt Kinetic Energy.

Graphene gas-barrier performance holds great interest from both scientific and technological perspectives. Using in situ synchrotron X-ray photoelectron spectroscopy, we demonstrate that chemical vapor-deposited monolayer graphene loses its gas-barrier performance almost completely when oxygen molecules are imparted with sub-electronvolt kinetic energy but retains its gas-barrier performance when the molecules are not energized. The permeation process is nondestructive. Molecular dynamics-based simulation suggests kinetic energy-mediated chemical reactions catalyzed by common graphene defects as a responsible mechanism.

[A case of dihydropyrimidine dehydrogenase (DPD) deficiency with severe side effects from UFT/Uzel administration].

5-FU is among the drugs most frequently used in the treatment of gastrointestinal malignancies. Also, it has been reported to reveal severe side effects in the case of a dihydropyrimidine dehydrogenase (DPD) deficiency. A 75-year-old man showed severe nausea and vomiting after administration of UFT/Uzel as adjuvant chemotherapy. Because of severe thrombocytopenia and grade 4 neutropenia, platelet transfusion and G-CSF administration were performed. With time, the leukocyte, neutrophil and platelet count recovered to normal level. We strongly suspected a DPD deficiency from the result of urinary pyrimidine analysis.

[A case of advanced breast cancer leading to DIC after chemotherapy].

We reported a case of DIC who was administered FEC90 (5-FU 1,000 mg/body, epirubicin 170 mg/body, cyclophosphamide 1,000 mg/body) for advanced breast cancer. A 55-year-old woman was referred to our hospital with lumbago. There was a huge tumor in her left breast (10x10 cm) and bone scintigraphy showed multiple bone metastasis, so she was treated with FEC90. Before the third course, DIC occurred. The patient was then treated with FOY and heparin, and the DIC was resolved. We think the DIC of this case was related with tumor lysis syndrome. Febrile neutropenia has been occasionally emphasized during chemotherapy, but due care must be taken for lymphocyte depletion during treatment.

ICAM-1 expression and the soluble ICAM-1 level for evaluating the metastatic potential of gastric cancer.

ICAM-1 plays an important role in cell-cell and cell-extracellular matrix interactions, especially tumor invasion and cytotoxicity of lymphocytes. In the present study, the relationship between metastasis of gastric cancer and ICAM-1 expression by cancer cells or the serum level of s-ICAM-1 was (s-ICAM-1) was examined. ICAM-1 was detected by immunohistochemic staining in 49.0% of 108 patients with gastric cancer. The ICAM-1 expression rate was higher at a more advanced stage, based on lymph node metastasis, being 46.9% in node-negative and 56.1% in node-positive cases. In patients with liver metastasis, the rate was 90.9%, while it was 43.3% in patients without liver metastasis (p < 0.05). The serum s-ICAM-1 level was 262.1 ng/ml (median 205.5, range 176.0-271.0) in healthy subjects and 391.5 ng/ml (median 317.5, range 148.7-1,768.0) in gastric cancer patients (p < 0.001). The serum s-ICAM-1 level was significantly higher in patients with liver metastasis than in patients without liver metastasis (p < 0.0001). In addition, positive ICAM-1 expression cases had significantly higher s-ICAM-1 levels than negative ones, 408.9 +/- 188.4 and 308.1 +/- 88.1 ng/ml, respectively. These results suggested that ICAM-1 was overexpressed in cancer cells and released as s-ICAM-1, which would promote hematogenous metastasis by suppressing local anticancer immunity.