Large anisotropy in the magnetic susceptibility of metallic carbon nanotubes.

Through magnetic linear dichroism spectroscopy, the magnetic susceptibility anisotropy of metallic single-walled carbon nanotubes has been extracted and found to be 2-4 times greater than values for semiconducting nanotubes. This large anisotropy can be understood in terms of large orbital paramagnetism of metallic nanotubes arising from the Aharonov-Bohm-phase-induced gap opening in a parallel field, and our calculations quantitatively reproduce these results. We also compare our values with previous work for semiconducting nanotubes, which confirm that the magnetic susceptibility anisotropy does not increase linearly with the diameter for small-diameter nanotubes.

Possible phase transition deep inside the hidden order phase of ultraclean URu2Si2.

To elucidate the underlying nature of the hidden order (HO) state in heavy-fermion compound URu(2)Si(2), we measure electrical transport properties of ultraclean crystals in a high field, low temperature regime. Unlike previous studies, the present system with much less impurity scattering resolves a distinct anomaly of the Hall resistivity at H;{*} = 22.5 T, well below the destruction field of the HO phase = or approximately 36 T. In addition, a novel quantum oscillation appears above a magnetic field slightly below H;{*}. These results indicate an abrupt reconstruction of the Fermi surface, which implies a possible phase transition well within the HO phase caused by a band-dependent destruction of the HO parameter.

Immune response induced by airway sensitization after influenza A virus infection depends on timing of antigen exposure in mice.

To study which phase of viral infection promotes antigen sensitization via the airway and which type of antigen-presenting cells contributes to antigen sensitization, BALB/c mice were sensitized by inhalation of ovalbumin (OA) during the acute phase or the recovery phase of influenza A virus infection, and then 3 weeks later animals were challenged with OA. The numbers of eosinophils and lymphocytes, the amounts of interleukin-4 (IL-4) and IL-5 in the bronchoalveolar lavage fluid, and the serum levels of OA-specific immunoglobulin G1 (IgG1) and IgE increased in mice sensitized during the acute phase (acute phase group), while a high level of gamma interferon production was detected in those sensitized during the recovery phase (recovery phase group). In the acute phase group, both major histocompatibility complex class II molecules and CD11c were strongly stained on the bronchial epithelium; in the recovery phase group, however, neither molecule was detected. OA-capturing dendritic cells (DCs) migrated to the regional lymph nodes, and a small number of OA-capturing macrophages were also observed in the lymph nodes of the acute phase group. In the recovery group, however, no OA-capturing DCs were detected in either the lungs or the lymph nodes, while OA-capturing macrophages were observed in the lymph nodes. These results indicate that the timing of antigen sensitization after viral infection determines the type of immune response.

[Isoproterenol continuous nebulization of childhood status asthmaticus. II. Efficacy and side effects of low-dose method comparing with high-dose method].

We investigated the efficacy and side effects of "low-dose isoproterenol continuous nebulization" for childhood status asthmaticus, and compared them with those of "high-dose method". "Low-dose" is defined as 10 ml or less of 0.5% dl-isoproterenol solution diluted in 500 ml of normal saline. Subjects were 23 children who were hospitalized and underwent the nebulization therapy. The period of continuous nebulization was 26.3 +/- 12.5 hours. The Wood's clinical score clearly decreased in 22 cases, the average score changing from 7.3 +/- 1.2 to 2.8 +/- 1.5. Heart rate was not elevated significantly during the nebulization period, and decreased gradually (142 +/- 22/min at the start of the nebulization, 145 +/- 22/min at 1 hour, and 134 +/- 23/min at 3 hours, and 103 +/- 13/min at the cessation of the nebulization). Serum GOT, LDH, CPK, and potassium were decreased after the nebulization compared with the values before the treatment, the changes of the last 2 items being statistically significant. Two subjects who had vomited before the nebulization therapy complained nausea during the procedure, and one experienced transient finger tremor. We conclude that "low-dose isoproterenol continuous nebulization" is an effective and safe method for childhood status asthmaticus. We expect that this method will be familiar to all clinicians.

[Isoproterenol continuous nebulization for childhood status asthmaticus. I. Efficacy and side effects of high-dose method].

We investigated the efficacy and the side effects of "high-dose isoproterenol continuous nebulization" for childhood status asthmaticus. Subjects were 34 children who were hospitalized and underwent the nebulization therapy. The 50 ml solution of 0.5% dl-isoproterenol was diluted in 500 ml of normal saline and nebulized through an ultrasound nebulizer. The period of continuous nebulization was 25.5 +/- 16.0 hours. The Wood's clinical score clearly decreased in 32 cases, the average score changing from 7.7 +/- 0.8 to 2.9 +/- 1.3. Heart rate was elevated significantly during the first 3 hours (156 +/- 25/min at the start of the nebulization, 180 +/- 20/min at 1 hour, 171 +/- 23 at 3 hours), and then it decreased gradually to 122 +/- 25/min at the cessation of the nebulization. Serum GOT, LDH, CPK, and potassium were elevated after the nebulization compared with the values before the treatment, though the changes were not statistically significant. CPK-MB fraction after the nebulization was higher than normal range in 12 of 13 subjects. Of 34 subjects, 11 (32%) complained nausea or vomited, 2 showed arrhythmia on ECG (ventricular premature conduction), 1 developed myocardiac infarction, and 1 developed possible heart failure, some of which might be attributable to the pharmacological side effects of isoproterenol nebulization. We conclude that "high-dose isoproterenol continuous nebulization" is an effective method for childhood status asthmaticus, but there is some risk of serious side effects. This method was originally developed as a method indicated for the case of respiratory failure or threatened respiratory failure following status asthmaticus, and we should not extend the indication of this method thoughness.

[The accuracy of several brands of portable peak flow meter, and the predicted value of peak expiratory flow rate for children].

The accuracy, reproducibility and interdevice variability of 6 brands of peak flow meter were evaluated by using a flow generator. The accuracy was satisfiable except for Mini-Wright, which overread by up to 29%. It is essential to identify the brands to compare the data of peak expiratory flow rate (PEFR) from different studies. The reproducibility was under 5%, reliable enough for personal monitoring. The low range models were inferior to the normal range models as a whole. There are some studies about the normal value of PEFR for Japanese children. They have drawn different linear equations to obtain the predicted value of PEFR from the body height. However, none of them can be the "gold standard".