Grain boundary diffusion of W in lower mantle phase with implications for isotopic heterogeneity in oceanic island basalts by core-mantle interactions

Tungsten isotopes provide important constraints on the ocean-island basalt (OIB) source regions. Recent analyses of μ182W in modern basalts with high 3He/4He originating from the core-mantle boundary region reveal two distinct features: positive μ182W in Phanerozoic flood basalts indicating the presence of primordial reservoir, and negative μ182W in modern OIBs. One possibility to produce large variations in μ182W is interaction between the mantle and outer core. Here, we report grain boundary diffusion of W in lower mantle phases. High pressure experimental results show that grain boundary diffusion of W is fast and strongly temperature dependent. Over Earth's history, diffusive transport of W from the core to the lowermost mantle may have led to significant modification of the W isotopic composition of the lower mantle at length scales exceeding one kilometer. Such grain boundary diffusion can lead to large variations in μ182W in modern basalts as a function of the distance of their source regions from the core mantle boundary. Modern oceanic island basalts from Hawaii, Samoa and Iceland exhibit negative μ182W and likely originated from the modified isotope region just above the core-mantle boundary, whereas those with positive μ182W could be derived from the thick Large Low Shear Velocity Provinces (LLSVPs) far from the core-mantle boundary (CMB). When highly-oxidized slabs accumulate at the CMB oxidizing the outer core at the interface, a large W flux with negative μ182W can be added to the silicate mantle. As a result, the source region of the OIB would be effectively modified to a negative μ182W

Structured Water Molecules on Membrane Proteins Resolved by Atomic Force Microscopy

Water structuring on the outer surface of protein molecules called the hydration shell is essential as well as the internal water structures for higher-order structuring of protein molecules and their biological activities in vivo. We now show the molecular-scale hydration structure measurements of native purple membrane patches composed of proton pump proteins by a noninvasive three-dimensional force mapping technique based on frequency modulation atomic force microscopy. We successfully resolved the ordered water molecules localized near the proton uptake channels on the cytoplasmic side of the individual bacteriorhodopsin proteins in the purple membrane. We demonstrate that the three-dimensional force mapping can be widely applicable for molecular-scale investigations of the solid–liquid interfaces of various soft nanomaterials

Practical aspects of Kelvin-probe force microscopy at solid/liquid interfaces in various liquid media

The distributions of surface charges or surface potentials on biological molecules and electrodes are directly related to various biological functions and ionic adsorptions, respectively. Electrostatic force microscopy and Kelvin-probe force microscopy (KFM) are useful scanning probe techniques that can map local surface charges and potentials. Here, we report the measurement and analysis of the electrostatic and capacitive forces on the cantilever tip induced by application of an alternating voltage in order to discuss the feasibility of measuring the surface charge or potential distribution at solid/liquid interfaces in various liquid media. The results presented here suggest that a nanometer-scale surface charge or potential measurement by the conventional voltage modulation techniques is only possible under ambient conditions and in a non-polar medium and is difficult in an aqueous solution. Practically, the electrostatic force versus dc voltage curve in water does not include the minimum, which is used for the surface potential compensation. This is because the cantilever oscillation induced by the electrostatic force acting on the tip apex is overwhelmed by the parasitic oscillation induced by the electrostatic force acting on the entire cantilever as well as the surface stress effect. We both experimentally and theoretically discuss the factors which cause difficulties in application of the voltage modulation techniques in the aqueous solutions and present some criteria for local surface charge and potential measurements by circumventing these problems

Molecular resolution imaging of protein molecules in liquid using frequency modulation atomic force microscopy

金沢大学フロンティアサイエンス機構We demonstrated molecular resolution imaging of biological samples such as bacteriorhodopsin protein molecules in purple membrane and isolated chaperonin (GroEL) protein molecules, both adsorbed on mica using frequency modulation atomic force microscope (FM-AFM) in liquid. We also showed that the frequency noise of FM-AFM in liquid can be greatly reduced by the reduction of the noise-equivalent deflection of an optical beam deflection sensor. © 2009 The Japan Society of Applied Physics

Relationship between Cytologic Results and the Extent of Intraductal Spread in Nonpalpable Breast Cancers with Nipple Discharge

Cytologic results of smears and ductal washings for 51 consecutive cases of nonpalpable breast cancers with nipple discharge were studied. Noninvasive can-cer was confirmed in 40 cases and microinvasive in 11 cases. The cytologic results were compared with the extent of cancerous lesions which was measured as the angle of cancerous spread (Q) on a map made from histological prepara-tions. Although the sensitivity of cytologic examinations was quite low (9.8% and 33.3%), the cytologic results correlated with the extent of cancerous spread in the breast (P<0.01) and with the distance from the nipple to the lesion (P<0. 01). The results in this study suggest that cytologic results can be affected by the extent of cancerous spread. The results of cytologic examination should be made use of in the process of assessing the presence of extensive cancerous lesions which cause nipple dis-charge with no palpable mass

Deficiency of the RIβ subunit of protein kinase A causes body tremor and impaired fear conditioning memory in rats

The RIβ subunit of cAMP-dependent protein kinase (PKA), encoded by Prkar1b, is a neuronal isoform of the type I regulatory subunit of PKA. Mice lacking the RIβ subunit exhibit normal long-term potentiation (LTP) in the Schaffer collateral pathway of the hippocampus and normal behavior in the open-field and fear conditioning tests. Here, we combined genetic, electrophysiological, and behavioral approaches to demonstrate that the RIβ subunit was involved in body tremor, LTP in the Schaffer collateral pathway, and fear conditioning memory in rats. Genetic analysis of WTC-furue, a mutant strain with spontaneous tremors, revealed a deletion in the Prkar1b gene of the WTC-furue genome. Prkar1b-deficient rats created by the CRISPR/Cas9 system exhibited body tremor. Hippocampal slices from mutant rats showed deficient LTP in the Schaffer collateral–CA1 synapse. Mutant rats also exhibited decreased freezing time following contextual and cued fear conditioning, as well as increased exploratory behavior in the open field. These findings indicate the roles of the RIβ subunit in tremor pathogenesis and contextual and cued fear memory, and suggest that the hippocampal and amygdala roles of this subunit differ between mice and rats and that rats are therefore beneficial for exploring RIβ function

High-dose Chemotherapy with Peripheral Blood Stem Cell (PBSCT) Support for Recurrent Breast Cancer

Between May 1995 and June 1999 Seven patients with recurrent breast cancer received high dose chemotherapy (HDCT) with autologous peripheral blood stem cell transplantation (PBSCT) . The HDCT regimen consisted of epirubicin (120-260 mg/m? ), cyclophosphamide (0-4000 mg/body) . Medroxy-progesterone (1200 mg/day) was given more than 2 weeks prior to induction chemotherapy. HDCT with PBSCT support was performed on all patients on schedule. No toxic death by chemotherapy occurred. The clinical response was CR in 3, PR in 3 and NC in one patient. The rate of good clinical re-sponse was 86 %. The mean survival duration after recurrence was 24 months (range10-34) . The mean survival period after HDCT was 12 months (range 8-25) . The durations of efficacy were shorter than had been ex-pected. While this treatment resulted in higher rates of clinical response, the prognosis for patients with metastatic tumor was not improved