489 research outputs found
Conformation of ultra-long-chain fatty acid in lipid bilayer: Molecular dynamics study
Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in the restricted
tissues such as retina, testis, and skin. The conformation of a single ULCFA,
in which the sn-1 unsaturated chain has 32 carbons, in three types of
tensionless phospholipid bilayers is studied by molecular dynamics simulations.
It is found that the ultra-long tail of the ULCFA flips between two leaflets
and fluctuates among an elongation into the opposite leaflet, lying between two
leaflets, and turning back. As the number ratio of lipids in the opposite
leaflet increases, the ratio of the elongated shape linearly decreases in all
three cases. Thus, ULCFAs can sense the density differences between the two
leaflets and respond to these changes
Pneumatosis intestinalis leading to perioperative hypovolemic shock: Case report
Pneumatosis intestinalis (PI) is an uncommon disorder defined as multiple foci of gas within the intestinal wall. Despite recognition of an increasing number of cases of PI, the optimal management strategy, whether through surgical or other means, remains controversial. The present report describes the case of a patient with PI who underwent exploratory laparotomy without specific findings and who ultimately died due to extensive intestinal hemorrhage that was possibly triggered by surgery
Hole density dependence of effective mass, mobility and transport time in strained Ge channel modulation-doped heterostructures
We performed systematic low-temperature (T = 350 mK–15 K) magnetotransport measurements on the two-dimensional hole gas with various sheet carrier densities Ps = (0.57–2.1)×1012 cm–2 formed in the strained Ge channel modulation-doped (MOD) SiGe heterostructures grown on Si substrates. It was found that the effective hole mass deduced by temperature dependent Shubnikov–de Hass oscillations increased monotonically from (0.087±0.05)m0 to (0.19±0.01)m0 with the increase of Ps, showing large band nonparabolicity in strained Ge. In contrast to this result, the increase of the mobility with increasing Ps (up to 29 000 cm2/V s) was observed, suggesting that Coulomb scattering played a dominant role in the transport of the Ge channel at low temperatures. In addition, the Dingle ratio of the transport time to the quantum lifetime was found to increase with increasing Ps, which was attributed to the increase of remote impurity scattering with the increase of the doping concentration in MOD SiGe layers
数値シミュレーションによる二重膜の研究 : 化学反応下での形態変化と圧力分布計算手法
学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 陶山 明, 東京大学教授 新井 宗仁, 東京大学教授 能瀬 聡直, 東京大学教授 岡田 真人, 東京大学教授 岡田 康之University of Tokyo(東京大学
Gastrointestinal Stromal Tumor in a Patient with Neurofibromatosis: Abscess Formation in the Tumor Leading to Bacteremia and Seizure
A 66-year-old woman with neurofibromatosis type 1 (NF1) was brought to the emergency room with seizures and high-grade fever. Seizure in adult NF1 patients raises concern for intracranial lesions. However, neurological examination and central nervous system imaging failed to detect any causative intracranial lesions for her seizure. Gram-positive cocci, Streptococcus anginosus, were detected by blood cultures. Abdominal computed tomography revealed a well-defined round mass 7 cm in diameter, which was found to be a small intestinal gastrointestinal stromal tumor (GIST) containing an abscess. There was fistula formation between the intestinal lumen and the abscess, in which there were numerous Gram-positive cocci. The seizure may have been caused by hypoosmolality (hyponatremia and hypoproteinemia), which may result from decreased food intake associated with high-grade fever and general malaise. In this case GIST originating from the small intestine was invaded by S. anginosus through a fistula, leading to abscess formation, bacteremia, high-grade fever, and seizure, which was the first clinical manifestation
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