Ab-initio Molecular Dynamics Simulation of Li Insertion in C_<60>

Complexes composed of fullerenes and metal elements offer important examples as new nanomaterials in the field of materials design. In the collisions between C^-_ and Li^+ in plasma state, there is a possibility that the endohederal fullerene, Li@C_ is created as well as Li@C_ and so on. To study this phenomenon theoretically, we perform an all-electron mixed basis ab initio molecular dynamics simulation at 1, 000K which was developed by ourselves. When Li^+ with the kinetic energy ～5eV hits the center of a six-membered ring of C^-_, an endohedral complex, Li@C_ is created. This direcet insertion process is possible because the ionic radius of Li^+ is shorter then the radius of a six-membered ring. However, if either the kinetic energy is lower or the collision occurs off-center, the Li^+ ion stays outside and C_ is deformed by the shock

The Orientational Influence on the Electronic Structure of the Solid fcc C_<60>

The comparison of the electronic structures of fcc C_ solids between two different molecular orientations has been done by performing a band structure calculation. We have found that the molecular orientation causes considerable changes on the degeneracies at Γ points, the dispersion of bands and the location of valence band maximum and conduction band minimum. The band variation upon molecular orientation should become an important subject in physics and materials science of the new class of solid fullerenes

Dietary Modification of Mouse Response to Total-Body-Irradiation

Exposure to ionizing radiation (IR) could induce deleterious effects including cancer. Diet, as one of the major factors to influence susceptibility to many diseases, plays a critical role in maintaining human heath. It is known that unbalanced diet could result in health consequences, for example, high-calorie diet could lead to obesity, which could increase the risk of diabetes, heart disease, fatty liver, and some forms of cancer. Although the impact of diet on susceptibility to IR is thought to be big, the evidence is not clear due to lack of study. In this work, effects from dietary fat on modulation of mouse responses to total-body-irradiation (TBI) were studied. The mice were fed after weaning at postnatal age of 4 weeks with a standard diet (MB-1), a very high-fat diet (HFD32), and a very low-fat diet (CE-2 Low Fat), containing of 4.4%, 32.0%, and 0.4% of crude fat, respectively. A mouse model for radiation-induced adaptive response (AR) was applied to this work. The priming low-dose TBI at a dose of 0.5 Gy from X-rays was given at postnatal age of 6 weeks, and the challenge high dose of TBI was given at postnatal age of 8 weeks. The mouse response to low dose of TBI was evaluated by the efficacy of the priming low dose to rescue the animals from bone marrow death induced by the challenge high dose in the 30-day survival test. The mouse response to high dose of TBI was evaluated by comparing the LD50 in the 30-day survival test. In addition, dietary modulation of the residual (late) genotoxic effect from TBI was also evaluated by comparing the incidence of micronucleated erythrocytes in bone marrow using micronucleus test. Results showed that for the mice fed with the MB-1, a successful AR was demonstrated. While for the mice fed with either HFD32 or CE-2 Low Fat, no AR was observed, and all the animals died within 15 days after TBI with the challenge high dose at 7.5 Gy regardless the priming low dose at 0.5 Gy. When comparing the LD50 in the 30-day survival test, the LD50 values for the animals fed with the MB-1, HFD32 diet, and CE-2 Low Fat were 7.1 Gy, 6.0 Gy, and 6.2 Gy, respectively. As to the micronucleus test, for the mice fed with MB-1, the priming low dose at 0.5 Gy could significantly reduce the incidence of micronucleated erythrocytes in bone marrow that were caused by a challenge high dose at 4.0 Gy, while for the mice fed with either HFD32 or CE-2 Low Fat no such effect was observed. These findings indicated that under an unbalanced diet, namely, either of very high fat or of very low fat, alterations in mouse responses to TBI were induced. These findings confirmed that diet played a pivotal role in the response of the animals to radiation exposure, and suggested the possibility to modulate radiosensitivity through diet intervention in humans

AN AUTOPSY CASE OF PORTOPULMONARY HYPERTENSION ASSOCIATED WITH ALCOHOLIC LIVER CIRRHOSIS

We report an autopsy case of pulmonary pexogenic arteriopathy associated with portal hypertension due to alcoholic liver cirrhosis, termed portopulmonary hypertension (PPHT). A 49-year-old man who has had alcoholic liver cirrhosis for 10 years complained of severe dyspnea (Fletcher-Hugh-Jones V). Chest CT revealed marked enlargement of bilateral hilar pulmonary arteries and cardiomegaly associated with right ventricular hypertrophy. The patient died from hepatic. encephalopathy and respiratory failure. Autopsy c1early revealed the wall thickness of pulmonary small vessels diffusely in peripheral fields on cut surfaces and marked dilatation of the main pulmonary artery, together with liver cirrhosis. Microscopically, the pulmonary small arteries demonstrated grade 5 pulmonary plexogenic arteriopathy inc1uding plexiform lesions and a micronodule resembling an arachnoid granulation or meningioma throughout the lungs. This case suggested that a typical plexogenic arteriopathy morphologically and definitely contributed to confirm PPHT, although the patient was c1inically suspected of hepatopulmonary syndrome (HPS)

Full-potential Mixed-basis Simulated Annealing Calculation of C_<60>

A new class of small carbon clusters called Fullerene, e.g. C_ discovered in 1985, is one of the most interesting nanoscale materials at present because of its unique shape and physical and chemical properties. In this paper, the electronic structure and the structural stability of the C_ microcluster are examined by means of dynamical simulated annealing. We apply mixed-basis fomalism in order to describe wave functions including accurately core and valence orbitals. The basis set of this scheme consists of both plane waves and atomic orbitals, incorporating all electrons and full-potential into calculation. The present method is superior to the standard approach using the plane wave expansion and a pseudopotential, with respect that strongly localized electron orbitals like 1s and 2p can be described with considerably limited number of basis functions

Diallyl Disulfide Mitigates DNA Damage and Spleen Tissue Effects After Irradiation

BACKGROUND Several factors found in foods are beneficial to human health and they may contribute to radiation protection. Taking food factors could be an easy way to reduce the effects of radiation after nuclear accidents, as well as secondary radiation risks after cancer radiotherapy or space missions. Here, diallyl disulfide (DADS), a component of garlic oil, was studied for its ability to mitigate radiation damage. MATERIAL AND METHODS We investigated the effects of DADS on micronucleus (MN) formation and apoptosis in HepG2 cells by use of 4-Gy X-ray irradiation. We also assessed the effects of DADS on radiation damage in vivo by evaluating MN formation in bone marrow cells in mice (BALB/c, 8-week-old females) after oral intake of DADS prior to irradiation with 4 Gy. Several tissue effects were also investigated. RESULTS The presence of DADS inhibited MN formation, whereas DADS had no influence on the radiation-induced inhibition of cell cycle progression in HepG2 cells. An increase in apoptosis in HepG2 cells was induced after irradiation, and this effect was stronger in the presence of DADS than in its absence. In mice, when DADS was administered daily for 3 days prior to irradiation, MN formation in irradiated mice was decreased. The decrease in MN formation in mice was greater with 0.5% DADS compared to 1% DADS. Moreover, an increase in spleen weight observed 3 weeks after irradiation was suppressed in mice administered DADS. CONCLUSIONS DADS is a potential radiation-protective agent that effectively mitigates DNA damage, and its effects in the spleen observed after irradiation may be related to inflammation and carcinogenesis