Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.     

Comparison of measured value and calculated value of multiplestability in forced-flow cooled superconductors

The multiple stability observed exclusively in forced-flow cooled superconductors is numerically calculated, and the result is quantitatively compared with the value measured by J.W. Lue et al. (1980). The calculated and measured values agreed well in certain cases, and did not in others. Based on this comparison, the effects of the transient heat transfer coefficient and ohmic heat generation on the quantitative prediction of stability are discussed. From this comparison, it is learned that a precise understanding of the transient heat transfer coefficient is essential for reliable predictions, and also that the ordinary evaluation method of ohmic heat generation, which considers the flux-flow resistance, tends to overevaluate the situation     

Removal of dissolved estrogen in sewage effluents by β-cyclodextrin polymer

Substances with estrogenic activity are found in effluents of municipal sewage plants and dairy farms. These effluents have the potential to induce feminization in male fish. In this study, cyclodextrin polymers (CDPs) that are insoluble in both polar and non-polar solvents were selected for the removal of dissolved estrogens in the effluent of a municipal sewage plant. The removal capacity of CDPs was high in the order of β-CDP ≥ γ-CDP ? α-CDP. The mechanism for adsorption of estrogens to β-CDP was not only due to a host-guest interaction as molecular recognition by β-cyclodextrin (β-CD), but also due to adsorption by the polymer matrix. β-CDP of 0.2% (w/v) removed 17β-estradiol (E2) of about 70% from 10⁻¹¹ mol/L, and more than 90% from ≥ 10⁻¹⁰ mol/L. The removal ratios of E2 in the presence of cholesterols, which are contained at higher concentrations than estrogens in sewage effluents and are adsorptive competitor for β-CDP, were about 85% at a cholesterol/E2 molar ratio of 100 and > 90% at molar ratios of 0.1, 1, and 10. The effluent from a municipal sewage plant had estrogenic activity corresponding to 5.5 × 10⁻¹¹ molE2/L by yeast two-hybrid assay. The estrogens in the effluent were also removed > 90% by the β-CDP treatment. Therefore, β-CDP is able to remove dissolved estrogens over a wide range of concentrations in the presence of various contaminants such as wastewaters.     

Upregulation of angiotensin-converting enzyme during the healing process after injury at the site of percutaneous transluminal coronary angioplasty in humans

BACKGROUND: Balloon injury models in rat have shown enhanced expression of ACE in the developing neointima. However, neointimal lesions in human coronary arteries are complex due to atherosclerosis and different types of wall laceration. This study was designed to investigate whether ACE is present in the neointima of humans, including patients with restenosis after percutaneous transluminal coronary angioplasty (PTCA). METHODS AND RESULTS: Thirty-seven sites with angioplasty injury, obtained at autopsy, were studied using immunocytochemical techniques. Sites with injury limited to a fibrous plaque and those with injury extending into the media (<2 months after PTCA) showed fibrocellular repair tissue composed mainly of smooth muscle cells that were distinctly positive for ACE. In cellular reactions at the site of injury limited to the atheromatous plaque (<2 months after PTCA), the expression of ACE appeared first in accumulated macrophages; once smooth muscle cells appeared in the repair tissue, they also expressed ACE. At a later stage (3 months after PTCA), the number of cells with ACE expression decreased markedly; from 7 months on, ACE was no longer expressed within the repair tissue. Basically, there were no differences with regard to ACE expression during the healing process after PTCA between segments with and those without angiographic evidence of restenosis. CONCLUSIONS: These results show that PTCA injury in humans results in upregulation of ACE at sites of active repair and, therefore, ACE could play an important role as one of the mediators of the healing process after PTCA.     

Polyhydrides of Sc,Zr and Hf and Their Proposed Formation.

Hydrogenation at 500 psi of (PNP)Sc(CH₃)₂ results in formation of a trinuclear polyhydride complex [(PNP)Sc]₃(μ₂-H)₄(μ₃-H)₂ ( 1 ) in 55 % yield. The solid-state structure shows a non-symmetric trinuclear species resulting from one pincer phosphine arm being demetallated, and where two hydrides bridge all three Sc centers, whereas the other four bridge two. Hydrogenation of (PNP)Zr(CH₃)₃ at 200 psi results instead in formation of a dinclear polyhydride species [(PNP)Zr(H)]₂(μ₂-H)₄ ( 2 ). Conducting the hydrogenation at atmospheric pressure, resulted instead in formation of the bridging methylidene complex [(PNP)Zr(CH₃)]₂(μ₂-H)₂(μ₂-CH₂) ( 3 ), which cleanly converted to 2 , upon hydrogenation at higher pressure. Both 2 and 3 were also structurally characterized. Hydrogenation of (PNP)Hf(CH₃)₃ at 200 psi resulted in incomplete hydrogenation with some formation of dinuclear mono- and dimethyl-polyhydride complexes [(PNP)Hf(CH₃)]₂(μ₂-H)₄ ( 4 ) and [(PNP)Hf(CH₃)][(PNP)Hf(H)](μ₂-H)₄ ( 5 ), which were identified by solid-state X-ray structural studies. Based on these results, we propose a pathway for the complete hydrogenation of (PNP)Zr(CH₃)₃ to 2 .     

Development of incremental deep drawing process

This paper deals with development of an incremental deep drawing process. On a newly developed incremental deep drawing set-up, the aluminium sheets are formed; the forming is carried out by deep-drawing the blank as in the conventional method but incrementally. Fractures at the punch or die corner in the blank may or may not occur depending on the conditions; the process parameters involved are punch size, punch corner radius, increment in punch displacement, blank holding force or pressure, etc. It is thus shown that different shapes are formed by one set of common tools. It is thereby confirmed that incremental deep drawing is possible without using a particular tool set for a particular shape.