Development of a Novel Gas-Sensing Platform Based on a Network of Metal Oxide Nanowire Junctions Formed on a Suspended Carbon Nanomesh Backbone

Junction networks made of longitudinally connected metal oxide nanowires (MOx NWs) have been widely utilized in resistive-type gas sensors because the potential barrier at the NW junctions leads to improved gas sensing performances. However, conventional MOx-NW-based gas sensors exhibit limited gas access to the sensing sites and reduced utilization of the entire NW surfaces because the NW networks are grown on the substrate. This study presents a novel gas sensor platform facilitating the formation of ZnO NW junction networks in a suspended architecture by growing ZnO NWs radially on a suspended carbon mesh backbone consisting of sub-micrometer-sized wires. NW networks were densely formed in the lateral and longitudinal directions of the ZnO NWs, forming additional longitudinally connected junctions in the voids of the carbon mesh. Therefore, target gases could efficiently access the sensing sites, including the junctions and the entire surface of the ZnO NWs. Thus, the present sensor, based on a suspended network of longitudinally connected NW junctions, exhibited enhanced gas response, sensitivity, and lower limit of detection compared to sensors consisting of only laterally connected NWs. In addition, complete sensor structures consisting of a suspended carbon mesh backbone and ZnO NWs could be prepared using only batch fabrication processes such as carbon microelectromechanical systems and hydrothermal synthesis, allowing cost-effective sensor fabrication

Solstice: An Electronic Journal of Geography and Mathematics, Volume XIV, Number 2

This document was delivered over the internet. The .zip file contains all static images, animated images, and text files.The purpose of Solstice is to promote interaction between geography and mathematics. Articles in which elements of one discipline are used to shed light on the other are particularly sought. Also welcome, are original contributions that are purely geographical or purely mathematical. These may be prefaced (by editor or author) with commentary suggesting directions that might lead toward the desired interaction. Contributed articles will be refereed by geographers and/or mathematicians. Invited articles will be screened by suitable members of the editorial board. IMaGe is open to having authors suggest, and furnish material for, new regular features.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58247/2/win03.ziphttp://deepblue.lib.umich.edu/bitstream/2027.42/58247/3/2003SolsticeVol14.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/58247/5/SolsticeVolXIVNo2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/58247/6/SolsticeVolXIVNo2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/58247/8/SolsticeVolXIVNo2.pdfDescription of SolsticeVolXIVNo2.pdf : Cover of JournalDescription of 2003SolsticeVol14.pdf : Solstice, 2003, Numbers 1 and 2. Contains attachments.Description of SolsticeVolXIVNo2.pdf : Cover of JournalDescription of SolsticeVolXIVNo2.pdf : Cover fil

Solstice: An Electronic Journal of Geography and Mathematics, Volume XVI, Number 1

This document was delivered over the internet. The .zip file contains all static images, animated images, and text files.The purpose of Solstice is to promote interaction between geography and mathematics. Articles in which elements of one discipline are used to shed light on the other are particularly sought. Also welcome, are original contributions that are purely geographical or purely mathematical. These may be prefaced (by editor or author) with commentary suggesting directions that might lead toward the desired interaction. Contributed articles will be refereed by geographers and/or mathematicians. Invited articles will be screened by suitable members of the editorial board. IMaGe is open to having authors suggest, and furnish material for, new regular features.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58253/2/sum05.ziphttps://deepblue.lib.umich.edu/bitstream/2027.42/58253/3/SolsticeVolXVINo1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/58253/5/SolsticeVolXVINo1.pdfDescription of SolsticeVolXVINo1.pdf : Cover of JournalDescription of SolsticeVolXVINo1.pdf : Cover fil

Ann Arbor, Michigan: Virtual Downtown Experiments, Part III

To view the virtual reality, the internet browser must be enabled to read .vrml files.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60298/1/MAP.zi

Bacterial Ulcerative Esophagitis in an Immunocompetent Patient

Bacterial esophagitis is a very rare condition usually occurring in patients with immunosuppression. To our best knowledge, bacterial esophagitis without underlying immunosuppressive disease has not been reported. We report an immunocompetent patient with bacterial esophagitis caused by B-hemolytic Streptococcus which resulted in an esophageal stricture. A 68-year-old female was admitted for odynophagia which had developed several days before. Upper endoscopy revealed extensive ulceration covered by whitish exudates with submucosal edema at the proximal esophagus. She was treated with steroids and empirical broad-spectrum antibiotics. Within 14 days the symptoms improved. Since growth of B-hemolytic Streptococcus was detected in nasal smear culture, bacterial esophagitis was suspected. Gram staining was carried out on the already obtained tissue that had been fixed with formalin. There was heavy infiltration with gram-positive cocci morphologically consistent with Streptococcus. Since the bacterial colony was demonstrated histologically, the diagnosis of bacterial esophagitis caused by B-hemolytic Streptococcus was confirmed. In addition, complete resolution of the inflammation following antibiotics therapy was further evidence of the bacterial cause of the esophagitis

Batch Nanofabrication of Suspended Single 1D Nanoheaters for Ultralow-Power Metal Oxide Semiconductor-Based Gas Sensors

The demand for power-efficient micro-and nanodevices is increasing rapidly. In this regard, electrothermal nanowire-based heaters are promising solutions for the ultralow-power devices required in IoT applications. Herein, a method is demonstrated for producing a 1D nanoheater by selectively coating a suspended pyrolyzed carbon nanowire backbone with a thin Au resistive heater layer and utilizing it in a portable gas sensor system. This sophisticated nanostructure is developed without complex nanofabrication and nanoscale alignment processes, owing to the suspended architecture and built-in shadow mask. The suspended carbon nanowires, which are batch-fabricated using carbon-microelectromechanical systems technology, maintain their structural and functional integrity in subsequent nanopatterning processes because of their excellent mechanical robustness. The developed nanoheater is used in gas sensors via user-designable localization of the metal oxide semiconductor nanomaterials onto the central region of the nanoheater at the desired temperature. This allows the sensing site to be uniformly heated, enabling reliable and sensitive gas detection. The 1D nanoheater embedded gas sensor can be heated immediately to 250 degrees C at a remarkably low power of 1.6 mW, surpassing the performance of state-of-the-art microheater-based gas sensors. The presented technology offers facile 1D nanoheater production and promising pathways for applications in various electrothermal devices

Nocatriones A and B, Photoprotective Tetracenediones from a Marine-Derived <i>Nocardiopsis</i> sp.

Two new tetracenedione derivatives, nocatriones A (<b>1</b>) and B (<b>2</b>), were discovered from the culture broth of a marine actinomycete, <i>Nocardiopsis</i> sp. KMF-002, which was isolated from the tissue of an unidentified dark purple marine sponge. The structures of <b>1</b> and <b>2</b>, which are tetracenediones containing α-pyrone substituents, were determined to be 3,8,10,11-tetrahydroxy-2-(4-hydroxy-2-oxo-2<i>H</i>-pyran-6-yl)-1-methyltetracene-5,12-dione (<b>1</b>) and 3,8,10,12-tetrahydroxy-2-(4-hydroxy-2-oxo-2<i>H</i>-pyran-6-yl)-1-methyltetracene-6,11-dione (<b>2</b>). Ultraviolet B (UVB)-irradiated cells treated with 10 μM nocatrione A (<b>1</b>) significantly decreased the level of MMP-1, a protein that degrades collagen and other extracelluar matrix components that comprise dermal tissue, when compared to untreated cells. These results support that nocatriones A (<b>1</b>) and B (<b>2</b>) may show antiphotoaging activity in UVB-irradiated models

Anti-Human Rhinoviral Activity of Polybromocatechol Compounds Isolated from the Rhodophyta, Neorhodomela aculeata

An extract of the red alga, Neorhodomela aculeata, exhibited antiviral activity against human rhinoviruses. Bioassay-guided purification was performed to yield six compounds, which were subsequently identified as lanosol (1) and five polybromocatechols (2–6) by spectroscopic methods, including 1D and 2D NMR and mass spectrometric analyses. Structurally, all of these compounds, except compound 5, contain one or two 2,3-dibromo-4,5-dihydroxyphenyl moieties. In a biological activity assay, compound 1 was found to possess antiviral activity with a 50% inhibitory concentration (IC50) of 2.50 μg/mL against HRV2. Compound 3 showed anti-HRV2 activity, with an IC50 of 7.11 μg/mL, and anti-HRV3 activity, with an IC50 of 4.69 μg/mL, without demonstrable cytotoxicity at a concentration of 20 μg/mL. Collectively, the results suggest that compounds 1 and 3 are candidates for novel therapeutics against two different groups of human rhinovirus