Atmospheric Gas-Phase Catalyst Etching of SiO2 for Deep Microfabrication Using HF Gas and Patterned Photoresist.

Micro/nanoscale structure fabrication is an important process for designing miniaturized devices. Recently, three-dimensional (3D) integrated circuits using SiO2 via-holes interlayer filling by copper have attracted attention to extend the lifetime of Moore's law. However, the fabrication of vertical and smooth-sidewall via-hole structures on SiO2 has not been achieved using the conventional dry etching method due to the limitation of the selective etching ratio of SiO2 and hard mask materials. In this study, we developed a unique method for the deep anisotropic dry etching of SiO2 using atmospheric gas-phase HF and a patterned photoresist. The hydroxyl groups in the photoresist catalyzed the HF gas-phase dry etching of SiO2 at high-temperature conditions. Therefore, fabrication of vertical with smooth-sidewall deep microstructures was demonstrated in the photoresist-covered area on SiO2 at a processing rate of 1.3 µm/min, which is 2-3 times faster than the conventional dry etching method. Additionally, the chemical reaction pathway in the photoresist-covered area on SiO2 with HF gas was revealed via density functional theory (DFT) calculations. This simple and high-speed microfabrication process will expand the commercial application scope of next-generation microfabricated SiO2-based devices.

Fabrication of Superhydrophobic Nanostructures on Glass Surfaces Using Hydrogen Fluoride Gas.

Water-repellent glass surfaces have become increasingly important to ensure clear visibility in outdoor cameras, sensors, and automotive windows. In this study, we investigated a process for the formation of nanoscale structures on a glass surface using chemical reactions with hydrogen fluoride gas. Using this approach, nanostructures with superhydrophobicity, superhydrophilicity, and antireflective properties were formed on glass surfaces with minimal processing time. This mask-free method, working at atmospheric pressure, can be efficiently integrated within the float process, a mainstream manufacturing technique for flat glass, to introduce nanostructures onto the glass surface. Notably, after treatment with (1-H, 1-H, 2-H, 2-H-tridecafluorooctyl)trimethoxysilane (FAS-13), a typical hydrophobic agent, the resulting surface exhibited a maximum water contact angle of 162°. Owing to its low reflectivity and superhydrophobicity, this surface is anticipated to find applications in not only the design of architectural window glass and vehicle windows but also the development of solar panels and sensor cover glass for autonomous vehicles.

Three-dimensional ordering of water molecules reflecting hydroxyl groups on sapphire (001) and α-quartz (100) surfaces.

Water molecules on oxide surfaces influence the chemical reactivity and molecular adsorption behavior of oxides. Herein, three-dimensional atomic force microscopy (3D-AFM) and molecular dynamics simulations are used to visualize the surface hydroxyl (OH) groups and their hydration structures on sapphire (001) and α-quartz (100) surfaces at the atomic-scale. The obtained results revealed that the spatial density distributions and hydrogen-bonding strengths of surface OH groups affect their local hydration structures. In particular, the force curves obtained by 3D-AFM suggest that the hydration forces of water molecules intensify at sites where water molecules strongly interact with the surface OH groups. The insights obtained in this study deepen our understanding of the affinities of Al2O3 and SiO2 for water molecules and contribute to the use of 3D-AFM in the investigation of atomic-scale hydration structures on various surfaces, thereby benefiting a wide range of research fields dealing with solid-liquid interfaces.

Higher Toughness of Metal-nanoparticle-implanted Sodalime Silicate Glass with Increased Ductility.

In this report, we propose a novel framework for toughening brittle oxide glass originated from enhanced ductility by implanting a secondary material comprising different mechanical properties. To do so, copper-metal nanoparticles are implanted into the subsurface layer of commercial soda-lime silica glass by using the electrofloat method. The crack initiation load of the implanted glass is found to be comparable to the glass chemically strengthened in ordinary tempering conditions. By observing crack propagation and stress distribution from cross-section, it is found that the crack propagation stops within the metal nanoparticle implanted layer, due to the stress dissipation or relaxation. The copper-implanted glass shows improved toughness with decreased hardness. The toughening mechanism of the composite glass is theoretically studied using molecular dynamics calculations on an amorphous silica model with copper nanoparticles embedded, and Peridynamics fracture simulations for indentation on a glass sheet model whose surface was implicitly modeled as the copper-implanted oxide glass. The experimentally observed phenomena of intrinsic toughening were well explained by the series of the conducted simulations.

A case of diaphragmatic hernia following colonoscopy.

An 89-year-old woman with a history of traumatic injury was referred to our hospital for further evaluation of anemia. Two days after colonoscopy, she complained of intermittent abdominal pain. An abdominal computed tomography confirmed a left diaphragmatic defect with a herniated transverse colon. She underwent elective laparoscopic repair of the diaphragmatic hernia. Colonoscopy rarely causes or worsens a diaphragmatic hernia. This is a rare case where we observed the development and exacerbation of a diaphragmatic hernia. It is important to pay attention to the development of a diaphragmatic hernia after colonoscopy for patients with a history of traumatic injury.

[Multiple gastrointestinal stromal tumors during nilotinib treatment for chronic myelogenous leukemia in a patient with neurofibromatosis type 1].

A 60-year-old woman with neurofibromatosis type 1 presented to our hospital with melena. She reported a 1-year history of treatment with nilotinib hydrochloride hydrate for chronic myelogenous leukemia. Contrast-enhanced abdominal computed tomography revealed multiple intestinal tumors that were subsequently diagnosed as gastrointestinal stromal tumors (GIST) using single-balloon enteroscopy. Although the tumors showed no significant change over 1 year, partial jejunal resection was performed to confirm the diagnosis. Immunohistochemically, the tumors were GIST.

Effects of bafilomycin A1, a vacuolar type H+ ATPase inhibitor, on the thermosensitivity of a human pancreatic cancer cell line.

PURPOSE: It has been known that the thermosensitivity of tumour cells can be increased by lowering intra-cellular pH (pHi) by inhibiting pHi control mechanisms. The pHi is partially controlled by transport of H+ from cytoplasm into endocytic and secretary systems in the cells mediated by vacuolar type H+ATPase and also by transport of H+ through plasma membrane. METHODS: This study investigated the effects the bafilomycine A1, an inhibitor of the vacuolar type H+ATPase and the EIPA, an inhibitor of the Na+/H+ exchanger in plasma membrane, on thermosensitivity of AsPC-1 cells, a human pancreatic cancer cell line. It also investigated the effects of combination of bafilomycine A1 and EIPA. RESULTS: The treatment of cancer cells with bafilomycine A1 or EIPA individually slightly lowered pHi of the cells in vitro and increased the thermosensitivity of the cells. CONCLUSION: The combination of these two drugs significantly lowered pHi and increased thermosensitivity of cancer cells in vitro and enhanced the heat-induced the growth delay of AsPC-1 tumours grown s.c in the legs of BALB/cA nude mice.

[A case of vulval extramammary Paget's disease associated with pancreatic cancer that was successfully treated with chemotherapy].

We report the case of an 84-year-old woman with vulval extramammary Paget's disease associated with pancreatic cancer who was successfully treated. At first, biweekly low-dose FP (cisplatin 10 mg/body, 5-fluorouracil 250 mg/body) was administered by intravenous infusion. Next, we attempted a regimen of gemcitabine (1,000 mg/body) was administered weekly by intravenous infusion. As a result, the size of the pruritic lesion of the vulva was reduced more than 50%, and the serum level of CA19-9 decreased clearly. These treatments would be a valid option in certain cases of pancreas cancer and extramammary Paget's disease.