A look inside epitaxial cobalt-on-fluorite nanoparticles with three-dimensional reciprocal space mapping using GIXD, RHEED and GISAXS.

In this work epitaxial growth of cobalt on CaF2(111), (110) and (001) surfaces has been extensively studied. It has been shown by atomic force microscopy that at selected growth conditions stand-alone faceted Co nanoparticles are formed on a fluorite surface. Grazing-incidence X-ray diffraction (GIXD) and reflection high-energy electron diffraction (RHEED) studies have revealed that the particles crystallize in the face-centered cubic lattice structure otherwise non-achievable in bulk cobalt under normal conditions. The particles were found to inherit lattice orientation from the underlying CaF2 layer. Three-dimensional reciprocal space mapping carried out using X-ray and electron diffraction has revealed that there exist long bright 〈111〉 streaks passing through the cobalt Bragg reflections. These streaks are attributed to stacking faults formed in the crystal lattice of larger islands upon coalescence of independently nucleated smaller islands. Distinguished from the stacking fault streaks, crystal truncation rods perpendicular to the {111} and {001} particle facets have been observed. Finally, grazing-incidence small-angle X-ray scattering (GISAXS) has been applied to decouple the shape-related scattering from that induced by the crystal lattice defects. Particle faceting has been verified by modeling the GISAXS patterns. The work demonstrates the importance of three-dimensional reciprocal space mapping in the study of epitaxial nanoparticles.

Proximity effects and exchange bias in Co/MnF2(111) heterostructures studied by x-ray magnetic circular dichroism.

Cobalt nano-structured ultrathin films were grown on orthorhombic MnF(2) by molecular beam epitaxy on CaF(2) epitaxial layers deposited on Si(111) substrates. The Co film was grown at room temperature. It was found to be polycrystalline, forming nano-islands with height≈diameter≤10 nm. X-ray absorption evidences the chemical stability of the Co/MnF(2) interface. Remarkably, x-ray magnetic circular dichroism (XMCD) demonstrates that the Co induces a net magnetization on the Mn ions close to the interface. The magnetic moments of these Mn ions couple antiparallel to the Co and rotate upon field reversal following the magnetization of the Co both below and high above the Néel temperature of MnF(2) (T(N) = 67 K). The density of coupled Mn moments is found to be temperature dependent, with an equivalent thickness of ~1.5 MnF(2) monolayers at 20 K, decreasing to about ~0.5 ML as the temperature is raised to 300 K. Interestingly, the intensity of the Mn XMCD signal appears to be related to the coercivity of the Co layer. This behavior is interpreted in terms of the competition between thermal fluctuations, exchange coupling between Co and Mn at the interface and, at low temperature, the antiferromagnetic order in MnF(2).

Effect of Reveromycin A on experimental tooth movement in OPG-/- mice.

In osteoprotegerin-deficient (OPG-/-) mice, osteoclast activity causes bone resorption to outpace bone formation, leading to the development of severe osteoporosis. Such mice are therefore useful for investigating the alveolar bone of patients with osteoporosis. Reveromycin A (RM-A) was recently identified as the unique agent acting on osteoclast activation. This study aimed to analyze the effect of RM-A on the orthodontic treatment of OPG-/- mice (a model of osteoporosis patients with high levels of bone turnover). We examined alveolar bone remodeling in OPG-/- and wild-type (WT) mice during continuous tooth movement. The orthodontic force was induced by means of a Ni-Ti closed-coil spring to move the maxillary first molar for 14 days. RM-A sodium salt (1 mg/kg) was administered intraperitoneally twice daily. In OPG-/- mice, the tooth movement distance was longer, alveolar bone resorption was enhanced, the osteoclast count was greater, and serum alkaline phosphatase and tartrate-resistant acid phosphatase levels were higher relative to those in WT mice. However, the administration of RM-A in OPG-/- mice reduced these parameters. We conclude that RM-A normalizes bone metabolism and loss of alveolar bone during continuous tooth movement in OPG-/- mice.

Geissoschizine methyl ether, an alkaloid in Uncaria hook, is a potent serotonin 1A receptor agonist and candidate for amelioration of aggressiveness and sociality by yokukansan.

Yokukansan (YKS), a traditional Japanese medicine, is composed of seven kinds of dried herbs. It is widely prescribed in clinical situation for treating psychiatric disorders such as aggressiveness in patients with dementia. We previously demonstrated that YKS and Uncaria hook (UH), which is a constituent herb of YKS, had a partial agonistic effect to 5-HT(1A) receptors in vitro. However, it has still been unclear whether this in vitro effect is reflected in in vivo, and what the active ingredients are. The purpose of the present study is to find the active ingredient in YKS and to demonstrate the effect in in vivo. In the present study, we first studied the effect of YKS and UH on aggressiveness and sociality in socially isolated mice. YKS and UH ameliorated the isolation-induced increased aggressiveness and decreased sociality, and these ameliorative effects were counteracted by coadministration of 5-HT(1A) receptor antagonist WAY-100635, or disappeared by eliminating UH from YKS. These results suggest that the effect of YKS is mainly attributed to UH, and the active ingredient is contained in UH. To find the candidate ingredients, we examined competitive binding assay and [(35)S] guanosine 5'-O-(3-thiotriphosphate) (GTPγS) binding assay of seven major alkaloids in UH using Chinese hamster ovary cells expressing 5-HT(1A) receptors artificially. Only geissoschizine methyl ether (GM) among seven alkaloids potently bound to 5-HT(1A) receptors and acted as a partial agonist. This in vitro result on GM was further demonstrated in the socially isolated mice. As did YKS and UH, GM ameliorated the isolation-induced increased aggressiveness and decreased sociality, and the effect was counteracted by coadministration of WAY-100635. These lines of results suggest that GM in UH is potent 5-HT(1A) receptor agonist and a candidate for pharmacological effect of YKS on aggressiveness and sociality in socially isolated mice.

Yokukansan, a traditional Japanese medicine, ameliorates memory disturbance and abnormal social interaction with anti-aggregation effect of cerebral amyloid ß proteins in amyloid precursor protein transgenic mice.

The deposition of amyloid ß protein (Aß) is a consistent pathological hallmark of Alzheimer's disease (AD) brains. Therefore, inhibition of Aß aggregation in the brain is an attractive therapeutic and preventive strategy in the development of disease-modifying drugs for AD. An in vitro study demonstrated that yokukansan (YKS), a traditional Japanese medicine, inhibited Aß aggregation in a concentration-dependent manner. An in vivo study demonstrated that YKS and Uncaria hook (UH), a constituent of YKS, prevented the accumulation of cerebral Aß. YKS also improved the memory disturbance and abnormal social interaction such as increased aggressive behavior and decreased social behavior in amyloid precursor protein transgenic mice. These results suggest that YKS is likely to be a potent and novel therapeutic agent to prevent and/or treat AD, and that this may be attributed to UH.

[Off-pump coronary artery bypass surgery for the ischemic cardiomyopathy patient with moderate mitral regurgitation and stenosis of bilateral vertebral arteries].

We report a 71-year-old man who had severe coronary and cerebral vascular disease with moderate mitral regurgitation (MR). Left ventricular reconstruction and mitral valve surgery were considered for poor left ventricular function and dilatation with MR. However, low blood pressure during cardiac arrest was risk for stroke due to severe stenosis of bilateral vertebral arteries. The myocardial viability of the anterior wall and inferior wall was confirmed by thallium-201 rest-redistribution single photon emission computed tomography (SPECT). Therefore, off-pump coronary artery bypass grafting (OPCAB) was selected for the patient. Only three Lima sutures were used for keeping the optimal heart position. Coronary anastomoses were done in sequence right gastroepiploic artery (RGEA)-#4 posterior descending (PD), left internal thoracic artery (LITA)-#9-#14 (sequential), RITA-#8 left anterior descending (LAD). No neurological complication occurred postoperatively. Left ventricular function and MR gradually improved. Final ejection fraction (EF) is 51% and MR is trivial. This case demonstrated improvement of MR by only revascularization according to preoperative viability assessment.

Neuroprotective effects of yokukansan, a traditional Japanese medicine, on glutamate-mediated excitotoxicity in cultured cells.

To clarify the mechanism of yokukansan (TJ-54), a traditional Japanese medicine, against glutamate-mediated excitotoxicity, the effects of TJ-54 on glutamate uptake function were first examined using cultured rat cortical astrocytes. Under thiamine-deficient conditions, the uptake of glutamate into astrocytes, and the levels of proteins and mRNA expressions of glutamate aspartate transporter of astrocytes significantly decreased. These decreases were ameliorated in a dose-dependent manner by treatment with TJ-54 (100-700 microg/ml). The improvement of glutamate uptake with TJ-54 was completely blocked by the glutamate transporter inhibitor DL-threo-beta-hydroxyaspartic acid. Effects of TJ-54 on glutamate-induced neuronal death were next examined by using cultured PC12 cells as a model for neurons. Addition of 17.5 mM glutamate to the culture medium induced an approximately 50% cell death, as evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. TJ-54 (1-1000 microg/ml) inhibited the cell death in a dose-dependent manner. Furthermore, competitive binding assays to glutamate receptors showed that TJ-54 bound potently to N-methyl-D-aspartate receptors, in particular, to its glutamate and glycine recognition sites. These results suggest that TJ-54 may exert a neuroprotective effect against glutamate-induced excitotoxicity not only by amelioration of dysfunction of astrocytes but also by direct protection of neuronal cells.

Development and evaluation of a loop-mediated isothermal amplification method for the rapid detection of Chlamydophila pneumoniae.

We developed a loop-mediated isothermal amplification (LAMP) method to detect Chlamydophila pneumoniae infection. This assay exclusively amplified C. pneumoniae sequences and no cross-reactivity was observed for other Chlamydia species. The detection limit for this assay was found to be ten elementary bodies in 25 min, as observed in a real-time turbidimeter and electrophoretic analysis. The specificity of the LAMP reaction was confirmed by restriction endonuclease analysis, as well as direct sequencing of the amplified product. Among nasopharyngeal swab specimens from 120 patients with acute respiratory tract infections and 40 healthy individuals, the LAMP results showed 100% agreement with the results of real-time polymerase chain reaction (PCR) assays.

Contaminant-associated disruption of vitamin A and its receptor (retinoic acid receptor alpha) in free-ranging harbour seals (Phoca vitulina).

Polychlorinated biphenyls (PCBs) have been associated with a number of toxic effects in marine mammals such as endocrine disruption and immunotoxicity that, in turn, are widely thought to have contributed to population level impacts including reproductive failure and outbreaks of disease. In this study, the dietary hormone vitamin A and expression levels of one of its receptors, retinoic acid receptor alpha (RARalpha), were used as biomarkers of PCB-associated health effects in harbour seals. Harbour seal pups (n=24) were live-captured in coastal British Columbia, Canada, and Washington State, USA, and sampled for whole blood (to obtain peripheral blood mononuclear cells, PBMCs) and blood plasma, as well as biopsies of blubber and skin. Concentrations of circulatory vitamin A (retinol) in plasma and stored vitamin A in blubber were negatively associated with blubber PCB concentrations (R=-0.518, p=0.013 and R=-0.645, p=0.009, respectively). However, vitamin A concentrations in skin, an important target tissue, remained constant, which likely reflects a compensatory transfer from blubber to maintain physiological functions. In addition, we characterized the harbour seal RARalpha, and investigated its expression levels as a potential biomarker in seals. RARalpha expression in blubber, but not on PBMCs, was elevated in more contaminated animals (R=0.580, p=0.009). This may represent a direct contaminant-related effect, or, a compensation for the contaminant-related disruption of (circulatory and/or blubber) hormone levels. Since vitamin A is critical to developmental, reproductive and immunological health, our observations of a contaminant-related disruption of its physiology in free-ranging seals may portend population level consequences. Vitamin A concentrations and RARalpha expression levels can therefore represent relevant and sensitive biomarkers of PCB-associated toxic effects in toxicological studies of marine mammals.

Enhancement of crude bone morphogenetic protein-induced new bone formation and normalization of endochondral ossification by bisphosphonate treatment in osteoprotegerin-deficient mice.

Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor family which plays a crucial role in negative regulation of osteoclastic bone resorption. We investigated both the quantity and quality of heterotopic new bone induced by crude bone morphogenetic protein (BMP) as a means of examining bone metabolism by bisphosphonate administration in OPG-/- mice. Four weeks after implantation of crude BMP, the volume of heterotopic new bone in OPG-/- mice without alendronate was significantly less than in wild-type (WT) mice. Alendronate treatment of OPG-/- mice resulted in enhancement of the volume of heterotopic new bone. Histological findings revealed that WT mice showed normal bone formation with persistent cartilage that was interspersed with islands of bone. In contrast, the cartilage was replaced by trabecular bone and bone marrow adipocytes in OPG-/- mice without alendronate. However, some cartilage was still present in OPG-/- mice with alendronate compared to those without alendronate. All bone formation-related parameters and bone resorption-related parameters were significantly lower in OPG-/- mice with alendronate than in those without alendronate. These findings suggest that in stimulated osteoclastogenesis without OPG, osteoinductive activity induced by crude BMP is inhibited and endochondral ossification induced by crude BMP is accelerated. On the other hand, alendronate treatment of OPG-/- mice caused osteoinductive activity induced by crude BMP to increase and endochondral ossification induced by crude BMP to be decelerated. In conclusion, inhibition of stimulated osteoclastogenesis results in the enhancement of new bone formation and normalization of endochondral ossification.

Lowest limit for detection of impurity concentration in semiconductors by fluorescence XAFS: resonant Raman scattering and angle dependence.

The lowest limit for detection (LLD) of the impurity concentration doped in semiconductors in the case of fluorescence XAFS measurements has been investigated as a function of the matrix of the impurity and the geometry of the measurement. When the impurity concentration is very low and other background noise is well suppressed, X-ray resonant Raman scattering by the constituent atoms of the matrix remains as a major background for the fluorescence-detected XAFS measurement. For example, in the fluorescence-detected XAFS measurement for Er-doped semiconductors at the Er L(III)-edge, the LLD of the Er concentration was about 5 x 10(14) to 1 x 10(15) cm(-2) for GaAs and GaP, and lower than 1 x 10(14) cm(-2) for InP. The resonant Raman scattering of Ga atoms in the host semiconductor determines the LLD.

Risk factors for occlusive lesions of intracranial arteries in stroke-free Japanese.

The aim of this study was to identify relevant risk factors for occlusive lesions of the intracranial arteries in stroke-free population. The subjects of this study were 425 patients without a history of stroke or transient ischemic attack and without any abnormality on a neurological examination who consecutively visited a neurology clinic between January 1994 and June 2001 requesting medical evaluation for possible cerebrovascular diseases. Subjects included 245 men and 180 women ranging in age from 33 to 89 years (mean+/-SD=64.0+/-10.0 years). We performed cervical and intracranial magnetic resonance angiography (MRA) in all subjects. Using a validated rating scheme of MRA for occlusive lesions, we evaluated the degree of stenoses in the extracranial portion of the internal carotid artery (ICA) and the intracranial arteries including the intracranial portion of the ICA, middle cerebral artery (MCA) stem, intracranial portion of the vertebral artery (VA), and basilar artery (BA). More than 25% stenoses were regarded as significant lesions in this study. Multiple logistic regression analyses showed that significant and independent predictors for extracranial ICA lesions were age, hyperlipidemia, and ischemic heart disease (IHD), those for intracranial ICA lesions were age, hypertension, diabetes mellitus, and IHD, those for MCA lesions were age and hypertension, those for intracranial VA lesions were hyperlipidemia and IHD, and those for BA lesions were hypertension and diabetes mellitus. The present study suggested that atherosclerosis of the intracranial VA was related to hyperlipidemia and IHD as was the case for the extracranial carotid artery, whilst atherosclerosis of other sites of intracranial arteries was associated with hypertension and diabetes mellitus in stroke-free Japanese.

Collection of reciprocal space maps using imaging plates at the Australian National Beamline Facility at the Photon Factory.

Weissenberg screens and a translating cassette have been employed to allow an imaging plate to collect 30 scans per readout. In this configuration the imaging plate functions as a curved one-dimensional position-sensitive detector and, by changing the sample angle for each of the scans, two-dimensional images were produced in reciprocal space. This method of data collection leads to a reduction in scan time compared with methods based on a scintillation detector, particularly for asymmetric reflections. The data-collection method was tested using InGaN/GaN/AlN multilayers on sapphire substrates, since these exhibit broad features in reciprocal space. The geometry of the scans in reciprocal space required the data to be interpolated onto a Cartesian grid. Several interpolation schemes were investigated, with the results compared with the reciprocal space maps collected using a triple-axis scheme with a point detector. The quality of the interpolated reciprocal space maps depends upon the size and shape of the feature in reciprocal space, the interpolation method used, and the step size of the sample rotation. The method can be extended to three dimensions without an increase in data-collection time.

Evolving atherosclerosis at carotid and intracranial arteries in Japanese patients with ischemic heart disease: a 5-year longitudinal study with MR angiography.

Progression of atherosclerosis at extracranial carotid and intracranial arteries in patients with ischemic heart disease (IHD) is not well defined. We carried out a 5-year longitudinal study with magnetic resonance angiography (MRA) of patients with IHD to assess the incidence of progression of atherosclerosis at extracranial carotid and intracranial arteries and to determine predictors of the progression. We previously performed carotid and intracranial MRA on 67 patients who had received selective coronary angiography for the clinical diagnosis of IHD. Of these 67 subjects, 41 patients gave informed consent to undergo MRA reexaminations to evaluate changes of extra- and intracranial arteries over a 5-year period. The degree of stenosis was divided into five grades depending on the narrowness of the arteries, i.e. normal, mild, moderate, severe and occluded. The average of follow-up period with MRA examination was 58.8 months. The progression of atherosclerosis, as defined as an increase of one grade of the stenosis rating, including both the exacerbation of pre-existing stenosis and the appearance of new stenotic lesions, were found in five patients (12.2%) for the cervical carotid artery and in only one patient (2.4%) for the intracranial artery. A multiple logistic regression analysis revealed that baseline carotid artery stenosis (P = 0.008), age (P = 0.047), and coronary events during the follow-up period (P = 0.048) were significant and independent predictors of progression of carotid atherosclerosis. In conclusion, our findings suggest that follow-up evaluation of the carotid artery is indicated for patients with IHD in whom carotid artery stenosis was detected on an initial examination. Further study is needed with larger numbers of patients to confirm these findings.

Different spatial processing for stimulus-centered and body-centered representations.

The authors describe a patient who experienced two successive strokes in the right hemisphere. After the first stroke, she showed stimulus-centered left neglect confined to right space on a circle discrimination task, which resolved. After the second stroke, she showed body-centered left neglect on the same task. These observations of two types of left neglect in the same patient suggest there are at least two distinct spatial attentional systems in the brain: global and focal attentional systems.

Brain activation during the fist-edge-palm test: a functional MRI study.

The purpose of our study is to clarify, using functional MRI, brain regions activated during the fist-edge-palm task (FEP) compared to relatively simple hand motor tasks using either the right or the left hand in right-handed normal volunteers. The FEP was introduced to detect a disorder of voluntary movement, and it is believed to be closely related to contralateral frontal lobe damage. However, this assumption still remains controversial. Ten subjects participated in this study. Hand motor tasks were as follows: (1) the FEP, in which the subjects were requested to place their hand in three different positions sequentially: a fist resting horizontally, a palm resting vertically, and a palm resting horizontally; (2) a fist-palm task (FP), in which the subjects were asked to clench and unclench their fist alternately; and (3) a control task requiring the subjects to knock lightly with their clenched fist. The contralateral sensomotor and premotor areas were activated in the FP with the right hand and the contralateral sensorimotor, premotor, and supplementary motor areas (SMA) were activated in the FP with the left hand. In the FEP with either hand, bilateral premotor and left parietal areas and ipsilateral cerebellum were also activated as well as contralateral sensorimotor area and SMA. Our results suggest that successful performance of the FEP requires the participation of more brain areas than FP, which may explain why some patients without frontal lobe damage failed to perform the FEP.

A separation carrier in high-speed proteome analysis by capillary electrophoresis.

We obtained a high-efficiency separation carrier for proteome analysis by capillary electrophoresis. The addition of curdlan or laminaran to the run buffer hastened the migration time without any degradation in resolution. We propose that for the development of the separation carrier it is necessary to synthetically analyze each of the following mobility factors of electroosmotic flow: buffer ionic strength, additional disturbance and adsorption. The total analysis for buffer and additive will be useful for designing high-throughput screening (HTS) systems for proteome analysis without annoying adsorption.

Referral and care for acute ischemic stroke in a Japanese tertiary emergency hospital.

To examine the current emergency referral and care for acute stroke at a Japanese tertiary emergency hospital with a 24-h stroke team and care unit, we surveyed the presentations of patients with acute ischemic stroke or transient ischemic attack (TIA) seen within 7 days of onset. Delay from symptom onset to arrival at our hospital, from arrival to initial diagnostic brain computed tomography (CT), and the type of anti-thrombotic treatments were evaluated. During the 18-month period, there were 254 ischemic events in 244 patients; 239 (94%) had an ischemic stroke and 15 (6%) TIA. Eighty-two (32%) events presented within 3 h of onset, and 102 (40%) and 179 (70%) within the first 6 and 24 h, respectively. The median delay from hospital arrival to CT was 32 min, ranging 10 min to 22 h. Two hundred (79%) events underwent CT within 1 h of arrival (n=172) or at the referral hospitals before transfer (n=28). Direct ambulance transportation and more severe neurological deficits were independent predictors both for early arrival and short in-hospital delay to CT. Anti-thrombotic therapies including anticoagulant and/or antiplatelet medications were given in 237 (93%) episodes. Two (1%) patients received thrombolysis, although 18 (7%) patients fulfilled the National Institute of Neurological Disorders and Stroke guidelines for intravenous thrombolysis with tissue plasminogen activator. As in western communities, our pre-hospital emergency referral systems for acute stroke require substantial improvements including the wider use of ambulance calling. Although our in-hospital stroke management is functioning relatively well, further efforts are necessary in reducing the diagnostic delay.

XAFS study of LiCo1-xFexO2 cathode for rechargeable lithium battery by laboratory XAFS spectrometer.

The change of local structure in layered-rock-salt-type iron doped lithium cobaltate LiCo(1-x)Fe(x)O2 under electrochemical Li de-intercalation (charge) /re-intercalation (discharge) was studied by a laboratory type XAFS spectrometer. In Co K-XANES and Fe K-XANES of LiCo0.85Fe0.15O2 the absorption peak shifted to higher energy by 1.5-2eV for Co K-edge and by 2-2.5eV for Fe K-edge, respectively, after the first charge. The spectra returned close to initial position and had almost original shape after the first discharge. In Co K- and Fe K-EXAFS of LiCo0.85Fe0.15O2 during the first charge and discharge the reversible change of the local structure was observed mainly around the Co atoms although the partly irreversible change of the local structure was found around the Fe atoms. The variation of local structure occurred in similar manner for the samples with x=0.05 and 0.25. This indicates that both Co3+/Co4+ and Fe3+/Fe4+ redox reactions occur reversibly during the first charge and discharge.