89 research outputs found
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
Glucose Tolerance and the Risk Factors for Transmission in Japanese SARS-CoV-2/WA-1/2020 Epicenter: A Retrospective Study
Manabu Saito,1,* Hiroshi Uchino,1,* Yoko Iwata,1 Ayako Fuchigami,1 Genki Sato,1 Fukumi Yoshikawa,1 Masahiko Miyagi,1 Taito Miyazaki,2 Yoshihisa Urita,2 Kotaro Aoki,3 Yoshikazu Ishii,3 Kazuhiro Tateda,3 Takahisa Hirose1 1Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University Graduate School of Medicine, Tokyo, Japan; 2Department of General Medicine and Emergency Care, Toho University School of Medicine, Tokyo, Japan; 3Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan*These authors contributed equally to this workCorrespondence: Hiroshi Uchino, Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Toho University Graduate School of Medicine, 6-11-1 Omori-nishi, Ota-ku, Tokyo, 143-8541, Japan, Tel +81-3-3762-4151, Fax +81-3-3765-6488, Email [email protected]: The severe pathogenic ancient-type COVID-19, SARS-CoV-2/WA-1/2020 was the predominant gene variant in early 2020 in Japan, however, its transmissibility was uncertain. The period before the public commenced using any personal protective equipment (PPE) was evaluating to describe the transmissibility of the SARS-CoV-2/WA-1/2020. We analyzed the secondary attack rate (SAR) among close contacts and the risk factor for SAR.Methods: This retrospective cohort study included a total of 539 patients who were anticipated for the SARS-CoV-2/WA-1/2020 infection at Toho University Medical Center Omori Hospital from February to May 2020. We selected 54 patients with 1) exclude other pathogens infection, 2) include āThree Csā condition: crowded places between distance 15min with a person tested positive for SARS-CoV-2/WA-1/2020 without PPE. We evaluated alternative infection risks: the body mass index (BMI) and diabetes (DM) status (non-DM, pre-DM, and DM) as demographic determinants of transmissibility and infectivity of SARS-CoV2/WA-1/2020 cases during the incubation period.Results: The calculated SAR was 79.3%. BMI was significantly associated with the PCR positivity rate, which was significant in the univariate (CI 95%, 1.02ā 1.51; P = 0.03) and multivariate (CI 95%, 1.02ā 1.60; P = 0.03) analyses. Comparing the different BMI groups, the highest BMI group (25.5ā 35.8 kg/m2) had an elevated risk of SAR compared to the lowest BMI group (14.0ā 22.8 kg/m2), with an odds ratio of 1.41 (95% CI, 1.02ā 1.59; P = 0.03). There were no significant differences in the risk of SAR among different DM statuses.Conclusion: The transmissibility of SARS-CoV2/WA-1/2020 was high (79.3%) among household members without PPE who had āThree Csā exposure. Although pre-DM and established DM did not confer a risk for transmissibility, higher BMI was associated with an increased risk of SAR.Trial Registration: UMIN Clinical Trials Registry, UMIN0000 50905.Keywords: obesity, pre-diabetes, SARS-CoV-2 transmissio
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
Steinert's syndrome presenting as anal incontinence: a case report
<p>Abstract</p> <p>Introduction</p> <p>Myotonic dystrophy (MD) or Steinert's syndrome is a rare cause of chronic diarrhea and anal incontinence. In the presence of chronic diarrhea and fecal incontinence with muscle weakness, neuromuscular disorders such as myotonic dystrophy should be considered in the differential diagnosis.</p> <p>Case Presentation</p> <p>We present the case of a 45-year-old Turkish man with Steinert's syndrome, who was not diagnosed until the age of 45.</p> <p>Conclusions</p> <p>In clinical practice, the persistence of diarrhea and fecal incontinence with muscle weakness should suggest that the physician perform an anal manometric study and electromyography. Neuromuscular disorders such as myotonic dystrophy should be considered in the differential diagnosis.</p
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<sup>Ā® </sup>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 <sup>13</sup>C 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 Ā± 0.86, (range, 0.9 - 5), versus 20.2 Ā± 18.9, (range, 5.1 - 159.4) for a positive one.</p> <p>Conclusions</p> <p>The BreathID<sup>Ā® </sup>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
Gastric cancer screening by combined assay for serum anti-Helicobacter pylori IgG antibody and serum pepsinogen levels ā āABC methodā
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, āABC methodā, 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(ā)PG(ā)], infection-free subjects; Group B [Hp(+)PG(ā)], chronic atrophic gastritis (CAG) free or mild; Group C [Hp(+)PG(+)], CAG; Group D [Hp(ā)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 50ā80% 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
Effect of nanoscale curvature sign and bundle structure on supercritical H2 and CH4 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
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 (ā¼800 K). Synchrotron X-ray diffraction shows a sharp structural transition of the one-dimensional sulphur occurring at ā¼450-650 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 ā¼90 GPa to become metallic
- ā¦