Task-Guided Selection of the Dual Neural Pathways for Reading

SummaryThe visual perception of words is known to activate the auditory representation of their spoken forms automatically. We examined the neural mechanism for this phonological activation using transcranial magnetic stimulation (TMS) with a masked priming paradigm. The stimulation sites (left superior temporal gyrus [L-STG] and inferior parietal lobe [L-IPL]), modality of targets (visual and auditory), and task (pronunciation and lexical decision) were manipulated independently. For both within- and cross-modal conditions, the repetition priming during pronunciation was eliminated when TMS was applied to the L-IPL, but not when applied to the L-STG, whereas the priming during lexical decision was eliminated when the L-STG, but not the L-IPL, was stimulated. The observed double dissociation suggests that the conscious task instruction modulates the stimulus-driven activation of the lateral temporal cortex for lexico-phonological activation and the inferior parietal cortex for spoken word production, and thereby engages a different neural network for generating the appropriate behavioral response

Synthesis and biological properties of two dimeric forms of human α-atrial natriuretic peptide

AbstractTwo dimeric forms of human α-atrial natriuretic peptide (α-ANP) were synthesized by solution methods and compared with monomeric α-ANP in terms of some biological and immunochemical properties. The parallel form (β'-ANP) and the antiparallel form (β-ANP) were equipotent in smooth muscle relaxant activity in isolated rat aorta and their ED50 values were estimated to be 1.7 × 10−8 M and 1.6 × 10−8 M, respectively. Diuretic and natriuretic responses induced by β-ANP and β'-ANP in anesthetized rats were equally less potent but exhibited a significantly longer duration than those induced by α-ANP. β-ANP and β'-ANP possessed immunoreactivities of 60–100% and 50–90% (α-ANP, 100% on a molar basis), respectively, with three different antisera raised against α-ANP-related peptides

Eigenspace Template Matching for Detection of Lacunar Infarcts on MR Images

Abstract Detection of lacunar infarcts is important because their presence indicates an increased risk of severe cerebral infarction. However, accurate identification is often hindered by the difficulty in distinguishing between lacunar infarcts and enlarged Virchow-Robin spaces. Therefore, we developed a computer-aided detection (CAD) scheme for the detection of lacunar infarcts. Although our previous CAD method indicated a sensitivity of 96.8 % with 0.71 false positives (FPs) per slice, further reduction of FPs remained an issue for the clinical application. Thus, the purpose of this study is to improve our CAD scheme by using template matching in the eigenspace. Conventional template matching is useful for the reduction of FPs, but it has the following two pitfalls: (1) It needs to maintain a large number of templates to improve the detection performance, and (2) calculation of the crosscorrelation coefficient with these templates is time consuming. To solve these problems, we used template matching in the lower dimension space made by a principal component analysis. Our database comprised 1,143 T 1 -and T 2 -weighted images obtained from 132 patients. The proposed method was evaluated by using twofold cross-validation. By using this method, 34.1 % of FPs was eliminated compared with our previous method. The final performance indicated that the sensitivity of the detection of lacunar infarcts was 96.8 % with 0.47 FPs per slice. Therefore, the modified CAD scheme could improve FP rate without a significant reduction in the true positive rate

Enhancement of superconducting properties in FeSe wires using a quenching technique

Enhancements of superconducting properties were observed in FeSe wires using a quenching technique. Zero resistivity was achieved at about 10 K in quenched wires, which is about 2 K higher than that of polycrystalline FeSe bulk. Furthermore, transport Jc of quenched wires showed three times higher than that of furnace-cooled wires. In contrast, the quenched polycrystalline FeSe bulks did not show the enhancement of Tc. The quenching technique is a greatly promising for fabricating FeSe wires with high Tc and high Jc, and quenched FeSe wires have high potential for superconducting wire applications

Scalable and template-free production of mesoporous calcium carbonate and its potential to formaldehyde adsorbent

Here we report a scalable and template-free production strategy 1 in the synthesis of a mesoporous calcium carbonate, which undergoes self-assembled nanostructure formation through a temperature-induced aggregation and polymorphic transformation of the colloids. The specific surface area and pore size distribution of resulting mesoporous calcium carbonate are clearly different depending on the aging temperature. The specific surface area and average pore size for aging temperature of 293 K are 207.3 ± 9.8 m2/g and 8.8±0.6 nm, respectively, and 65.1 ± 10.1 m2/g and 19.9±2.6 nm at 473 K. Additionally, we apply the mesoporous calcium carbonate powder to formaldehyde vapor adsorbent. We measure the adsorbed amount of gaseous formaldehyde and find that the vaterite-rich powder has larger adsorption per unit area than the calcite-rich one

Toxicoproteomic evaluation of carbon nanomaterials in vitro

Carbon nanotubes (CNTs) have already been successfully implemented in various fields, and they are anticipated to have innovative applications in medical science. However, CNTs have asbestos-like properties, such as their nanoscale size and high aspect ratio (> 100). Moreover, CNTs may persist in the body for a long time. These properties are thought to cause malignant mesothelioma and lung cancer. However, based on conventional toxicity assessment systems, the carcinogenicity of asbestos and CNTs is unclear. The reason for late countermeasures against asbestos is that reliable, long-term safety assessments have not yet been developed by toxicologists. Therefore, a new type of long-term safety assessment, different from the existing methods, is needed for carbon nanomaterials. Recently, we applied a proteomic approach to the safety assessment of carbon nanomaterials. In this review, we discuss the basic concept of our approach, the results, the problems, and the possibility of a long-term safety assessment for carbon nanomaterials using the toxicoproteomic approach.ArticleJournal of Proteomics. 74(12):2703-2712 (2011)journal articl

Correlation of histopathology with magnetic resonance imaging in Kienböck disease.

PURPOSE:Diagnosis and treatment remain controversial for Kienböck disease. A few reports have correlated magnetic resonance imaging (MRI), which is essential for early diagnosis, and histopathology of Kienböck biopsy specimens, but histopathological correlations of whole lunate bones or histological slices compared with MRI images are lacking. The purpose of this study was to compare presurgical MRI scans with corresponding histological slices of Kienböck-diseased lunates.METHODS:We excised whole lunates at the time of surgery from 6 patients with Kienböck disease (stage IIIB) undergoing tendon-ball replacement or a Graner procedure. We stained paraffin-embedded, coronally sectioned specimens with hematoxylin-eosin and compared them with presurgical coronal scans using MRI with a 47-mm microscopy surface coil.RESULTS:Toward the center of the lunates, the signal intensity in the proton density-weighted images was reduced, whereas the dorsal and palmar sides of the lunates exhibited no changes in intensity. In correlation, histopathological findings revealed strongly disrupted trabeculae toward the center of the lunates and intact trabeculae in the dorsal side of the lunates. Likewise, the necrotic and vitalized bone exhibited low and high signal intensities, respectively, in the proton density-weighted images; however, in the fast-field echo images, there were no correlations with histopathological observations.CONCLUSIONS:Proton density-weighted MRIs but not fast-field echo images using a 47-mm microscopy coil reflected the extent and localization of the necrotic area in Kienböck-diseased lunates, as evidenced by comparison with histological analyses of the lunate specimens.CLINICAL RELEVANCE:Proton density-weighted MRIs accurately reflect the vascular status of the lunate and may help plan treatment on a case-by-case basis

DJ-1 as a potential biomarker for the development of biocompatible multiwalled carbon nanotubes

Hisao Haniu1, Tamotsu Tsukahara2, Yoshikazu Matsuda3, Yuki Usui4, Kaoru Aoki5, Masayuki Shimizu5, Nobuhide Ogihara5, Kazuo Hara5, Seiji Takanashi5, Masanori Okamoto5, Norio Ishigaki5, Koichi Nakamura5, Hiroyuki Kato5, Naoto Saito6 1Institute of Carbon Science and Technology, 2Department of Integrative Physiology and Bio-System Control, Shinshu University, Matsumoto, Nagano, 3Clinical Pharmacology Educational Center, Nihon Pharmaceutical University, Ina-machi, Saitama, 4Research Center for Exotic Nanocarbons, 5Department of Orthopaedic Surgery, 6Department of Applied Physical Therapy, Shinshu University School of Health Sciences, Shinshu University, Matsumoto, Nagano, Japan Background: In the present study, we investigated whether DJ-1 could serve as a biomarker for assessing the biocompatibility of multiwalled carbon nanotubes (MWCNTs), using the highly purified carbon nanotube, HTT2800. Methods: Using Western blot analysis, we determined DJ-1 protein levels in two different types of cells (one capable and the other incapable of HTT2800 endocytosis). Using quantitative real-time polymerase chain reaction, we also investigated the ability of purified nanotubes to alter DJ-1 mRNA levels. Results: We demonstrated that the DJ-1 protein concentration was reduced, regardless of the cytotoxic activity of intracellular HTT2800. Furthermore, HTT2800 decreased the DJ-1 mRNA levels in a dose-dependent manner. This decrease in DJ-1 mRNA levels was not observed in the case of Sumi black or cup-stacked carbon nanotubes. Conclusion: These data indicate that modification of DJ-1 expression is caused by the cell response to MWCNTs. We conclude that DJ-1 is a promising candidate biomarker for the development of biocompatible MWCNTs. Keywords: multiwalled carbon nanotubes, DJ-1 protein, Western blot, quantitative real-time polymerase chain reactio