Buckling of Carbon Nanotubes: A State of the Art Review

The nonlinear mechanical response of carbon nanotubes, referred to as their "buckling" behavior, is a major topic in the nanotube research community. Buckling means a deformation process in which a large strain beyond a threshold causes an abrupt change in the strain energy vs. deformation profile. Thus far, much effort has been devoted to analysis of the buckling of nanotubes under various loading conditions: compression, bending, torsion, and their certain combinations. Such extensive studies have been motivated by (i) the structural resilience of nanotubes against buckling and (ii) the substantial influence of buckling on their physical properties. In this contribution, I review the dramatic progress in nanotube buckling research during the past few years.Comment: 38 pages, 21 figure

Mid-infrared transmission spectra of individual Antarctic micrometeorites and carbonaceous chondrites

Mid-infrared absorption spectra were obtained for 6 carbonaceous chondrites and 6 Antarctic micrometeorites (AMMs) with transmission light using an IR microscope. Obvious absorption bands caused by O-H stretching vibration at 3400cm^ and H-O-H bending vibration at 1640cm^ were detected for CI, CM2,CR2,and CO3 chondrites. All the chondrite samples had Si-O stretching band at around 1000cm^. Allende (CV3) exhibited only Si-O stretching band at near 900cm^ and no O-H bands. Infrared absorption spectra for AMMs showed no O-H stretching vibration reflecting their dry condition, except for F97AC019 and F97AC017 with weak O-H stretching band. Heating experiments on the grains of Murchison and Orgueil with sizes as small as AMMs (∿100μm) were carried out in order to clarify the dehydration effect of micrometeorite during the atmospheric entry. Heating times were 30 and 60s at temperatures every 100℃ from 500℃ to 1000℃. At relatively lower temperature condition (≤700℃), water in carbonaceous chondrites was not depleted. O-H stretching vibration at 3400cm^ was, however, vanished at higher temperature (≥800℃). This might show that AMMs were heated to 800℃ or more during atmospheric entry if our hearting duration is reasonable. Noble gas measurement using laser heating was performed for individual AMMs after the infrared microscopic analyses. Solar-He was detected for 4 samples. F97AC019 with very high concentration of helium (8.1×10^cm^3 STP/g) preserve solar-Ne and primordial trapped argon component. We have discovered an extraordinary AMM, F97AC021,with highly concentrated organic matters. Intense C-H stretching vibration at 2900cm^ and complex absorption pattern appeared in the range from 1400cm^ to 1800cm^ were detected. The AMM might have a potential to have plenty of extraterrestrial organic compounds

BNIP3 Plays Crucial Roles in the Differentiation and Maintenance of Epidermal Keratinocytes

Transcriptome analysis of the epidermis of Hes1−/− mouse revealed the direct relationship between Hes1 (hairy and enhancer of split-1) and BNIP3 (BCL2 and adenovirus E1B 19-kDa-interacting protein 3), a potent inducer of autophagy. Keratinocyte differentiation is going along with activation of lysosomal enzymes and organelle clearance, expecting the contribution of autophagy in this process. We found that BNIP3 was expressed in the suprabasal layer of the epidermis, where autophagosome formation is normally observed. Forced expression of BNIP3 in human primary epidermal keratinocytes (HPEKs) resulted in autophagy induction and keratinocyte differentiation, whereas knockdown of BNIP3 had the opposite effect. Intriguingly, addition of an autophagy inhibitor significantly suppressed the BNIP3-stimulated differentiation of keratinocytes, suggesting that BNIP3 plays a crucial role in keratinocyte differentiation by inducing autophagy. Furthermore, the number of dead cells increased in the human epidermal equivalent of BNIP3 knockdown keratinocytes, which suggests that BNIP3 is important for maintenance of skin epidermis. Interestingly, although UVB irradiation stimulated BNIP3 expression and cleavage of caspase3, suppression of UVB-induced BNIP3 expression led to further increase in cleaved caspase3 levels. This suggests that BNIP3 has a protective effect against UVB-induced apoptosis in keratinocytes. Overall, our data provide valuable insights into the role of BNIP3 in the differentiation and maintenance of epidermal keratinocytes

Appearance of ferromagnetism in Pt(100) ultrathin films originated from quantum-well states with possibility of small orbital magnetic moment

Ferromagnetism was observed in a Pt(100) ultrathin film deposited on a SrTiO3(100) substrate. The ferromagnetism, which appears in films with thicknesses of 2.2-4.4 nm, periodically changes with a period of approximately 1 nm (5-6 ML) depending on the film thickness. This is consistent with the period derived from the quantum-well states formed in the thin film. X-ray magnetic circular dichroism measurements were conducted to understand the intrinsic nature of the ferromagnetism in the Pt(100) ultrathin films, and contrary to our expectations, the orbital magnetic moment of pure Pt is much smaller than that of the Pt/ferromagnetic multilayer system. These results suggest that the origin of the large magnetic anisotropy in Pt components cannot be explained only by the amount of spin-orbit coupling in Pt.Comment: 7 pages, 4 figure

The effect of acotiamide on epigastric pain syndrome and postprandial distress syndrome in patients with functional dyspepsia

The effect of acotiamide on gastrointestinal symptoms is undefined. The aim of this study is to evaluate the effect of acotiamide on abdominal symptoms in patients with functional dyspepsia. We retrospectively reviewed 51 patients treated with acotiamide. We evaluated patient quality of life using the Izumo scale that detects changes in quality of life caused by abdominal symptoms. Acotiamide ameliorated the symptoms of functional dyspepsia at one and three months (improved : 61% vs 80%, p=0.029 and resolved : 17% vs 33%, p=0.069). We then evaluated the effect of acotiamide on epigastric pain syndrome (EPS) (n=33) and postprandial distress syndrome (PDS) (n=41). Acotiamide treatment showed an early effect on rates of improvement (63%) and resolution (42%) of EPS symptoms at one month, maintained up to three months (69% and 39%, respectively). Both rates of improvement and resolution of PDS symptoms showed a significant increase from one month to three months (56% vs 78%, p=0.021 and 17% vs 46%, p=0.004, respectively). The severity of functional dyspepsia symptoms before treatment was significantly associated with failed resolution of functional dyspepsia symptoms (p=0.013). Acotiamide improves and resolves EPS symptoms as well as PDS symptoms. PDS symptoms take longer to resolve than EPS symptoms

Advanced Treatment and Imaging in Colonoscopy: The Pocket-Creation Method for Complete Resection and Linked Color Imaging for Better Detection of Early Neoplastic Lesions by Colonoscopy

Early detection and resection of neoplastic lesions are key objectives to diminish colorectal cancer mortality. Resection of superficial colorectal neoplasms, cold snare polypectomy, endoscopic mucosal resection, and endoscopic submucosal dissection have all been developed and used worldwide. The pocket-creation method facilitates the resection of tumors in difficult and routine locations. Early detection is the most important first step to maximize the benefits of recent advancements in endoscopic techniques. However, the detection of small, flat-shaped, or faded color lesions remains difficult. Linked color imaging, a novel multi-light technology, facilitates the recognition of minor differences in tissue by enhancing the color contrast between early colorectal neoplasms and surrounding normal mucosa in a bright field of view. The most striking feature of linked color imaging is its ability to display the color of early neoplastic lesions as distinct from inflammatory changes, both of which have similar “redness” when viewed using white light imaging. To increase the detection rate of neoplasms, linked color imaging should be used from the outset for endoscopic observation. Early detection of superficial colorectal tumors can result in decreased mortality from colorectal cancer and maintain a good quality of life for patients

Linked Color Imaging and Blue Laser Imaging for Upper Gastrointestinal Screening

White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication. LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI

Blue Laser Imaging with a Small-Caliber Endoscope Facilitates Detection of Early Gastric Cancer

Conventional endoscopy often misses early gastric cancers with minimal red discoloration because they cannot be distinguished from inflamed mucosa. We treated a patient with a small early gastric cancer that was difficult to diagnose using conventional endoscopy. Conventional endoscopy using a small-caliber endoscope showed only subtle red discoloration of the gastric mucosa. However, blue laser imaging showed a clearly discolored area measuring 10 mm in diameter around the red lesion, which was distinct from the surrounding inflamed mucosa. Irregular vessels on the tumor surface (suspicious for early gastric cancer) were observed even with small-caliber endoscopy. Biopsy revealed a well-moderately differentiated tubular adenocarcinoma, and endoscopic submucosal dissection was performed. Histopathological examination of the specimen confirmed well-moderately differentiated adenocarcinoma localized to the mucosa with slight depression compared to the surrounding mucosa, consistent with the endoscopic findings. This small early gastric cancer became clearly visible with blue laser imaging using small-caliber endoscopy

Effects of muscle cooling on kinetics of pulmonary oxygen uptake and muscle deoxygenation at the onset of exercise

This study investigated effects of skeletal muscle cooling on the metabolic response and kinetics of pulmonary oxygen uptake (urn:x-wiley:2051817X:media:phy213910:phy213910-math-0001O2) and skeletal muscle deoxygenation during submaximal exercise. In the cooling condition (C), after immersion of the lower body into 12°C water for 30 min, eight healthy males performed 30‐min cycling exercise at the lactate threshold while undergoing thigh cooling by a water‐circulating pad. In the normal condition (N) as control, they conducted the same exercise protocol without cooling. Blood lactate concentration was significantly higher in C than N at 10 min after onset of exercise (4.0 ± 1.7 and 2.4 ± 1.2 mmol/L in C and N, P < 0.05). The percent change in the tissue oxygen saturation of the vastus lateralis, measured by a near‐infrared spectroscopy, was significantly lower in C at 2, 8, 10, and 20 min after the exercise onset compared with N (P < 0.05). The percent change in deoxy hemoglobin+myoglobin concentration (Deoxy[Hb+Mb]) showed a transient peak at the onset of exercise and significantly higher value in C at 10, 20, and 30 min after the exercise onset (P < 0.05). Compared to N, slower urn:x-wiley:2051817X:media:phy213910:phy213910-math-0002O2 kinetics (mean response time) was observed in C (45.6 ± 7.8 and 36.1 ± 7.7 sec in C and N, P < 0.05). The mean response time in C relative to N was significantly correlated with the transient peak of Deoxy[Hb+Mb] in C (r = 0.84, P < 0.05). These results suggest that lower oxygen delivery to the hypothermic skeletal muscle might induce greater glycolytic metabolism during exercise and slower urn:x-wiley:2051817X:media:phy213910:phy213910-math-0003O2 kinetics at the onset of exercise