Effect of pressure on single-chain magnets with repeating units of the MnIII-NiII-MnIII trimer

The single-chain magnet (SCM) system [Mn2(saltmen)2Ni(pao)2(L)2](A)2 (L: intrachain attaching ligand of NiII ion; A-1: interchain counteranion) is a ferromagnetic one-dimensional network system with repeating units of the MnIII-NiII-MnIII trimer which itself behaves as a single-molecule magnet with an S=3 spin ground state and negative uniaxial single-ion anisotropy (D) parallel to the bridging direction. The slow relaxation of the magnetic moment in this SCM system originates in an energy barrier for spin reversal (ΔE), which is closely related to the ferromagnetic interaction between the trimers (Jtrimer) as well as to the D of the trimer. We have investigated the effects of pressure on three compounds representative of the above SCM family through ac susceptibility measurements under hydrostatic pressures up to P=13.5 kbar and crystal structural analysis experiments up to P=20.0 kbar, and have observed a pronounced enlargement of ΔE when J was artificially increased. The application of hydrostatic pressure brought about the systematic enhancement of EΔ (a maximum increase of 10% within the pressure region of the experiments). The pressure dependence of EΔ varied according to the kind of attaching ligand L involved and the intrachain structure, and we have experimentally found that isotropic lattice shrinkage is desirable if a continuous increase of ΔE in this system is aimed at

Spin correlation and relaxational dynamics in molecular-based single-chain magnets

We report the combined measurements of the dc susceptibility X0, the ac susceptibility X, and the NMR relaxation rate T for the molecular-based heterometallic single-chain magnet [Mn(saltmen)]2[Ni(pao)2(py)2](PF6)2. At low temperatures, this system is well described by a one-dimensional array of effective spin S=3 chains comprising the MnIII-NiII-MnIII trimers and treated as the S=3 Ising chain with the single-ion term (Blume-Capel model). Using the exact solution of the model and based on the picture that the random motion of the local domain walls dominates the low-temperature spin dynamics, we succeeded in reproducing the experimental results of the dc susceptibility X0, the ac susceptibility X, and the 19F-NMR relaxation rate T in a consistent manner

Spin correlation and relaxational dynamics in molecular-based single-chain magnets

We report the combined measurements of the dc susceptibility 0, the ac susceptibility , and the NMR relaxation rate T for the molecular-based heterometallic single-chain magnet [Mn(saltmen)]2[Ni(pao)2(py)2](PF6)2. At low temperatures, this system is well described by a one-dimensional array of effective spin S=3 chains comprising the MnIII-NiII-MnIII trimers and treated as the S=3 Ising chain with the single-ion term (Blume-Capel model). Using the exact solution of the model and based on the picture that the random motion of the local domain walls dominates the low-temperature spin dynamics, we succeeded in reproducing the experimental results of the dc susceptibility 0, the ac susceptibility , and the 19F-NMR relaxation rate T in a consistent manner

Laser-driven phase transitions in aqueous colloidal gold nanoparticles under high pressure : picosecond pump–probe study

Pump-probe transient extinction spectroscopy was applied to analyze 355-nm picosecond laser heating-induced phenomena of 60-nm-diameter aqueous gold nanoparticles (AuNPs) under a high pressure of 60 MPa. Kinetic spectroscopy revealed that a supercritical layer surrounding the AuNP nucleated with a lifetime of approximately 1 ns in its dynamic expansion and decay behavior for a fluence of 19.6 mJ cm−2. Moreover, we observed in the post-mortem transmission electron micrographs a number of fragments, a small percentage of size-reduced cores, and erupted particles, among the intact particles after 60 shots, suggesting that evaporation occurs under laser illumination. The particle temperature calculation indicated that evaporation begins with a liquid droplet AuNP surrounded by a supercritical layer at temperatures below the boiling point of gold. By applying high pressure, we are able to obtain a clear picture of the evaporation event, which was not possible at ambient pressure because the forming bubble caused particle temperatures to rise uncontrollably. In this study, we shed light on the critical role of the supercritical layer formed around the AuNP under high pressure during laser-induced evaporation.Pulsed-laser illumination of aqueous gold colloids under high pressure enables the evaporation from liquid droplets surrounded by supercritical water layer

Validation of ozone data from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES)

The Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) onboard the International Space Station provided global measurements of ozone profiles in the middle atmosphere from 12 October 2009 to 21 April 2010. We present validation studies of the SMILES version 2.1 ozone product based on coincidence statistics with satellite observations and outputs of chemistry and transport models (CTMs). Comparisons of the stratospheric ozone with correlative data show agreements that are generally within 10%. In the mesosphere, the agreement is also good and better than 30% even at a high altitude of 73km, and the SMILES measurements with their local time coverage also capture the diurnal variability very well. The recommended altitude range for scientific use is from 16 to 73km. We note that the SMILES ozone values for altitude above 26km are smaller than some of the correlative satellite datasets; conversely the SMILES values in the lower stratosphere tend to be larger than correlative data, particularly in the tropics, with less than 8% difference below similar to 24km. The larger values in the lower stratosphere are probably due to departure of retrieval results between two detection bands at altitudes below 28km; it is similar to 3% at 24km and is increasing rapidly down below

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules

Objective: To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method: This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patientyears (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan-Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results: The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions: Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept

Protective Role of HLA-DRB1*13:02 against Microscopic Polyangiitis and MPO-ANCA-Positive Vasculitides in a Japanese Population: A Case-Control Study

Among antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV), granulomatosis with polyangiitis (GPA) and proteinase 3-ANCA-positive AAV (PR3-AAV) are prevalent in European populations, while microscopic polyangiitis (MPA) and myeloperoxidase-ANCA-positive AAV (MPO-AAV) are predominant in the Japanese. We previously demonstrated association of DRB1*09:01-DQB1*03:03 haplotype, a haplotype common in East Asians but rare in the European populations, with MPA/MPO-AAV, suggesting that a population difference in HLA-class II plays a role in the epidemiology of this disease. To gain further insights, we increased the sample size and performed an extended association study of DRB1 and DPB1 with AAV subsets in 468 Japanese patients with AAV classified according to the European Medicines Agency algorithm (MPA: 285, GPA: 92, eosinophilic GPA [EGPA]: 56, unclassifiable: 35) and 596 healthy controls. Among these patients, 377 were positive for MPO-ANCA and 62 for PR3-ANCA. The significance level was set at α = 3.3x10-4 by applying Bonferroni correction. The association of DRB1*09:01 with MPO-AAV was confirmed (allele model, P = 2.1x10-4, odds ratio [OR] = 1.57). Protective association of DRB1*13:02 was detected against MPO-AAV (allele model, P = 2.3x10-5, OR = 0.42) and MPA (dominant model, P = 2.7x10-4, OR = 0.43). A trend toward increased frequency of DPB1*04:01, the risk allele for GPA in European populations, was observed among Japanese patients with PR3-AAV when conditioned on DRB1*13:02 (Padjusted = 0.0021, ORadjusted = 3.48). In contrast, the frequency of DPB1*04:01 was decreased among Japanese patients with MPO-AAV, and this effect lost significance when conditioned on DRB1*13:02 (Padjusted = 0.16), suggesting that DRB1*13:02 or other allele(s) in linkage disequilibrium may be responsible for the protection. The differential association of DPB1*04:01 with PR3-AAV and MPO-AAV and difference in DPB1*04:01 allele frequencies between populations supported the hypothesis that the HLA-class II population difference may account in part for these epidemiologic characteristics. Furthermore, taken together with our previous observations, the haplotype carrying DRB1*13:02 was suggested to be a shared protective factor against multiple autoimmune diseases

Resection of lung metastasis from gallbladder carcinoma: immunohistochemistry of RCASI and CD8(+)T cells in primary and metastatic tumors

Advanced Gallbladder cancer has an extremely poor prognosis. We examined a patient with resectable gallbladder cancer with associated lung metastasis. A 64-year-old female patient, diagnosed with gallbladder cancer and a solitary benign lung tumor by imaging, was subjected to extensive cholecystectomy and extrahepatic bile duct resection. After one year, a follow-up CT indicated enlargement of the lung tumor; video-assisted right middle lobectomy was then performed. The lung tumor was diagnosed as a metastasis derived from the gallbladder cancer by pathology and immunohistochemistry. Expression of RCAS1, an independent unfavorable prognostic indicator in gallbladder cancer, was observed in both the gallbladder and lung tumors. However, infiltration of CD8+T cells was only seen in the lung metastatic tumor. She has remained free of any evidence of recurrence in the 10 months and 4 years after the first surgery. The results that metastasis is solitary and infiltrated by CD8+T cells correspond with the present clinical history