The ideal porous structure of EDLC carbon electrodes with extremely high capacitance

We propose an ideal porous structure of carbon electrodes for electric double-layer capacitors (EDLCs). The porous carbon successfully improved the gravimetric capacitance above ?200 F g?1 even in an organic electrolyte by utilizing the carbon nanopore surface more effectively. High-resolution transmission electron microscopy images and X-ray diffraction patterns classified 15 different porous carbon electrodes into slit-shape and worm-like-shape, and the pore size distributions of the carbons were carefully determined applying the grand canonical Monte Carlo method to N2 adsorption isotherms at 77 K. The ratio of pores where solvated ions and/or desolvated ions can penetrate also has a significant effect on the EDL capacitance as well as the pore shape. The detailed study on the effect of porous morphologies on the EDLC performance indicates that a hierarchical porous structure with a worm-like shaped surface and a pore size ranging from a solvated ion to a solvent molecule is an ideal electrode structure

Effect of nanoscale curvature sign and bundle structure on supercritical H(2) and CH(4) adsorptivity of single wall carbon nanotube

The adsorptivities of supercritical CH(4) and H(2) of the external and internal tube walls of single wall carbon nanotube (SWCNT) were determined. The internal tube wall of the negative curvature showed the higher adsorptivities for supercritical CH(4) and H(2) than the external tube wall of the positive curvature due to their interaction potential difference. Fine SWCNT bundles were prepared by the capillary force-aided drying treatment using toluene or methanol in order to produce the interstitial pore spaces having the strongest interaction potential for CH(4) or H(2); the bundled SWCNT showed the highest adsorptivity for supercritical CH(4) and H(2). It was clearly shown that these nanostructures of SWCNTs are crucial for supercritical gas adsorptivity.ArticleADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY. 17(3):643-651 (2011)journal articl

Ballistic- and quantum-conductor carbon nanotubes: A reference experiment put to the test

We have performed electrical transport experiments on individual carbon nanotubes (CNTs) in situ in a transmission electron microscope using the liquid-metal contact method (LMC method), which consists of immersing a CNT placed on the apex of a metallic tip into a drop of liquid mercury (Hg). In the literature, this method has been mostly employed without visualization (ex situ) to show the ballistic- and quantum-conductance properties of different kinds of CNTs. We show that on the one hand the in situ LMC method is well suited to create low-resistance contacts with the CNTs but on the other hand the ballistic and quantum conductance measured by the ex situ LMC method is likely to give false positives for three reasons: (a) the CNTs are likely to be removed from the tip surface through contact with the Hg, (b) occurring Hg-tip surface nanocontacts are likely to be mistaken for quantum-conductor CNTs, and (c) occurring Hg nanomenisci are likely to be mistaken for ballistic-conductor CNTs. These findings have strong consequences for the interpretation of previously reported works

Gastric cancer screening by combined assay for serum anti-Helicobacter pylori IgG antibody and serum pepsinogen levels — “ABC method”

The current status of screening for gastric cancer-risk (gastritis A, B, C, D) method using combined assay for serum anti-Helicobacter pylori (Hp) IgG antibody and serum pepsinogen (PG) levels, “ABC method”, was reviewed and the latest results of our ongoing trial are reported. It was performed using the following strategy: Subjects were classified into 1 of 4 risk groups based on the results of the two serologic tests, anti-Hp IgG antibody titers and the PG I and II levels: Group A [Hp(−)PG(−)], infection-free subjects; Group B [Hp(+)PG(−)], chronic atrophic gastritis (CAG) free or mild; Group C [Hp(+)PG(+)], CAG; Group D [Hp(−)PG(+)]), severe CAG with extensive intestinal metaplasia. Continuous endoscopic follow-up examinations are required to detect early stages of gastric cancer. Asymptomatic Group A, which accounts for 50–80% of all the subjects may be excluded from the secondary endoscopic examination, from the viewpoint of efficiency. Hp-infected subjects should be administered eradication treatment aimed at the prevention of gastric cancer

Applicability of a short/rapid 13C-urea breath test for Helicobacter pylori: retrospective multicenter chart review study

<p>Abstract</p> <p>Background</p> <p>Carbon labeled urea breath tests usually entail a two point sampling with a 20 to 30-minute gap. Our aim was to evaluate the duration of time needed for diagnosing <it>Helicobacter pylori </it>by the BreathID^®System.</p> <p>Methods</p> <p>This is a retrospective multicenter chart review study. Test location, date, delta over baseline, and duration of the entire test were recorded. Consecutively ¹³C urea breath tests results were extracted from the files over a nine year period.</p> <p>Results</p> <p>Of the 12,791 tests results, 35.1% were positively diagnosed and only 0.1% were inconclusive. A statistically significant difference in prevalence among the countries was found: Germany showing the lowest, 13.3%, and Israel the highest, 44.1%. Significant differences were found in time to diagnosis: a positive diagnosis had the shortest and an inconclusive result had the longest. Overall test duration averaged 15.1 minutes in Germany versus approximately 13 minutes in other countries. Diagnosis was achieved after approximately 9 minutes in Israel, Italy and Switzerland, but after 10 on average in the others. The mean delta over baseline value for a negative diagnosis was 1.03 ± 0.86, (range, 0.9 - 5), versus 20.2 ± 18.9, (range, 5.1 - 159.4) for a positive one.</p> <p>Conclusions</p> <p>The BreathID^®System used in diagnosing <it>Helicobacter pylori </it>can safely shorten test duration on average of 10-13 minutes without any loss of sensitivity or specificity and with no test lasting more than 21 minutes.</p

Conducting linear chains of sulphur inside carbon nanotubes

Despite extensive research for more than 200 years, the experimental isolation of monatomic sulphur chains, which are believed to exhibit a conducting character, has eluded scientists. Here we report the synthesis of a previously unobserved composite material of elemental sulphur, consisting of monatomic chains stabilized in the constraining volume of a carbon nanotube. This one-dimensional phase is confirmed by high-resolution transmission electron microscopy and synchrotron X-ray diffraction. Interestingly, these one-dimensional sulphur chains exhibit long domain sizes of up to 160 nm and high thermal stability (∼800 K). Synchrotron X-ray diffraction shows a sharp structural transition of the one-dimensional sulphur occurring at ∼450-650 K. Our observations, and corresponding electronic structure and quantum transport calculations, indicate the conducting character of the one-dimensional sulphur chains under ambient pressure. This is in stark contrast to bulk sulphur that needs ultrahigh pressures exceeding ∼90 GPa to become metallic

Anisakiasis: The risks of seafood consumption

Context and Aims: Japanese cuisine is now popular worldwide, and consumption of raw fish has thus increased at sushi bars and Japanese restaurants outside Japan. Anisakiasis, also known as herring‑worm disease, is caused by ingesting larval nematodes in raw seafood and is a common illness in Japan. However, due to the rising popularity of Japanese food, gastroenterologists outside Japan need to be familiar with this disease.Subjects and Methods and Results: We treated 158 patients presenting with acute gastrointestinal manifestations caused by anisakiasis from April 1991 to April 2000. One or more nematodes were removed endoscopically within 48 h of presentation in 44% of these patients, which resulted in prompt resolution of symptoms. Major endoscopic findings were gastric ulcer accompanied by hemorrhage, erosion, redness, and edema of the gastric mucosa in areas penetrated by larvae and other areas.Conclusions: Endoscopy was valuable for the diagnosis and treatment of anisakiasis. We recommend endoscopy in suspected cases of anisakiasis. Moreover, it is desirable to combine complementary tests such as immunological tests/IgE measurement. As the popularity of Japanese cuisine increases, reports of anisakiasis are likely to be more frequent in countries other than Japan.Keywords: Anisakiasis, Anisakis, herring worm, Japanese cuisine, Pseudoterranova, raw fis