To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Decreased hemoglobin levels increase the risk of developing dementia among the elderly. However, the underlying mechanisms that link decreased hemoglobin levels to incident dementia still remain unclear, possibly due to the fact that few studies have reported on the relationship between low hemoglobin levels and neuroimaging markers. We, therefore, investigated the relationships between decreased hemoglobin levels, cerebral small-vessel disease (CSVD), and cortical atrophy in cognitively healthy women and men.
Cognitively normal women (n = 1,022) and men (n = 1,018) who underwent medical check-ups and magnetic resonance imaging (MRI) were enrolled at a health promotion center. We measured hemoglobin levels, white matter hyperintensities (WMH) scales, lacunes, and microbleeds. Cortical thickness was automatically measured using surface based methods. Multivariate regression analyses were performed after controlling for possible confounders.
Decreased hemoglobin levels were not associated with the presence of WMH, lacunes, or microbleeds in women and men. Among women, decreased hemoglobin levels were associated with decreased cortical thickness in the frontal (Estimates, 95% confidence interval, −0.007, (−0.013, −0.001)), temporal (−0.010, (−0.018, −0.002)), parietal (−0.009, (−0.015, −0.003)), and occipital regions (−0.011, (−0.019, −0.003)). Among men, however, no associations were observed between hemoglobin levels and cortical thickness.
Our findings suggested that decreased hemoglobin levels affected cortical atrophy, but not increased CSVD, among women, although the association is modest. Given the paucity of modifiable risk factors for age-related cognitive decline, our results have important public health implications.
Epidemiological studies have reported that higher education (HE) is associated with a reduced risk of incident Alzheimer's disease (AD). However, after the clinical onset of AD, patients with HE levels show more rapid cognitive decline than patients with lower education (LE) levels. Although education level and cognition have been linked, there have been few longitudinal studies investigating the relationship between education level and cortical decline in patients with AD. The aim of this study was to compare the topography of cortical atrophy longitudinally between AD patients with HE (HE-AD) and AD patients with LE (LE-AD).
We prospectively recruited 36 patients with early-stage AD and 14 normal controls. The patients were classified into two groups according to educational level, 23 HE-AD (>9 years) and 13 LE-AD (≤9 years).
As AD progressed over the 5-year longitudinal follow-ups, the HE-AD showed a significant group-by-time interaction in the right dorsolateral frontal and precuneus, and the left parahippocampal regions compared to the LE-AD.
Our study reveals that the preliminary longitudinal effect of HE accelerates cortical atrophy in AD patients over time, which underlines the importance of education level for predicting prognosis.
The modified TiO2 nanoparticles were incorporated into the Bulk heterojunction system of P3HT:PCBM to improve the performance of P3HT:PCBM bulk heterojunction organic solar cells. The organically-modified TiO2 nanoparticle compounds were synthesized in aqueous media at room temperature. These TiO2 compounds in various solution concentrations were deposited on the top of the P3HT:PCBM active layer by spin coating. The performance of organic solar cells was carefully investigated in the respect of the scattering and the localized surface plasmon resonance (LSPR) that couple strongly to the incident light. In addition to the device, P3HT:PCBM solar cells with the use of the TiO2 nanoparticles, enhanced Fill Factor (FF) due mainly to improved shunt resistance (Rsh). The TiO2 plays a critical role in improving the interface between P3HT:PCBM active layer and Al electrode.
Liquorice is one of the botanicals used frequently as a traditional medicine in the West and in the East. Platelet-derived growth factor (PDGF)-BB is involved in the development of CVD by inducing abnormal proliferation and migration of vascular smooth muscle cells. In our preliminary study, dehydroglyasperin C (DGC), an active compound of liquorice, showed strong antioxidant activity. Since phytochemicals with antioxidant activities showed beneficial effects on chronic inflammatory diseases, the present study aimed to investigate the effects of DGC on PDGF-induced proliferation and migration of human aortic smooth muscle cells (HASMC). Treatment of HASMC with DGC for 24 h significantly decreased PDGF-induced cell number and DNA synthesis in a dose-dependent manner without any cytotoxicity, as demonstrated by the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide test and thymidine incorporation. Upon cell cycle analysis, DGC blocked the PDGF-induced progression through the G0/G1 to S phase of the cell cycle, and down-regulated the expression of cyclin-dependent kinase (CDK); 2, cyclin E, CDK4 and cyclin D1. Furthermore, DGC significantly attenuated PDGF-stimulated phosphorylation of PDGF receptor-β, phospholipase C-γ1, AKT and extracellular-regulated kinase 1/2, and DGC inhibited cell migration and the dissociation of actin filaments by PDGF. In a rat vascular balloon injury model, DGC suppressed an excessive reduction in luminal diameters and neointimal formation compared with the control group. These results demonstrate the mechanistic basis for the prevention of CVD and the potential therapeutic properties of DGC.
This paper provides an overview of the development and application of the National Aquatic Ecological Monitoring Program (NAEMP) in Korea, which uses biological and habitat–riparian criteria for river/stream and watershed management. Development of NAEMP began in 2003, with recognition by the Korean Ministry of Environment (MOE) of the limitations of applying chemical parameters (e.g., biochemical oxygen demand (BOD)) as the principal targets of water environment management. Ecosystem health criteria under NAEMP were developed from 2003 to 2006. Candidate sites for monitoring were also screened and established across the country. NAEMP was implemented in 2007, and since then a standard protocol of nationwide monitoring based on multi-criteria has been implemented to assess the ecological condition of rivers and streams. The monitoring results indicate that many Korean rivers and streams are severely degraded, with biological conditions that are much worse than their water chemistry suggests. In 2009, 24% of rivers and streams were in classes C (Fair) and D (Poor) for BOD, but more than 71, 53, and 27% were categorized as Fair to Poor according to fish, diatom, and benthic macroinvertebrate assemblages, respectively. NAEMP is promising in that the results have already had great impacts on policy making and scientific research relevant to lotic water environment and watershed management in Korea. In the future, NAEMP results will be used to develop more aggressive regulations for the preservation and restoration of rivers/streams, riparian buffer areas and watersheds. Another future aim of the NAEMP is to develop aquatic ecological modeling based on the monitoring results.
Bonding process using indium-silver alloy which can withstand high temperature was investigated at relatively low temperature. We used a thermal evaporator and vacuum coater for making indium-silver contact. From the result of experiment, we observed that indium and silver films which have good quality are formed. From phase diagram of In-Ag alloy, we can find that melting point of these compounds increases with the silver content, i.e. eutectic (144° C) <AgIn2 (166° C) < (300° C) < (670° C) < (695° C). And these compounds are determined by the composition ratio of the source metal. Now we confirmed the thermal characteristics of Indium-Silver alloy is controlled by silver. Consequently we have developed Ag/In/Ag multi-layer composite which has higher melting point than that of normal contact. The melting point of Ag/In/Ag multi-layer is about 700° C. The joint cross-sections are studied using SEM(scanning electron microscopy) and EDX(Energy Dispersive X-rays). From these data, we observed that the composition and microstructure of Ag/In/Ag multi-layer were reliable and this bonding procedure is a better technique compared to the conventional structure of quantum well LED and GaN/Si LED structure was made by using sapphire for substrate and might be good for high temperature electronic devices in the future.
The advanced electrodes for detecting organophosphate pesticides were prepared by modification of the gold (Au) electrode with the reduced graphene oxide/ionic liquid (RGO/IL) nanohybrids. Due to the cationic and anionic parts, the ILs on RGO sheets provide the amount of functional groups for dispersion of hybrids and immobilization of organophosphorus hydrolase (OPH) enzymes. After the immobilization of OPH on the RGO/IL-modified Au electrodes, the modified electrodes represent faster electron transfer than that of Au electrode, resulting in high performance of biosensor with response time (~ 10 s) and sensitivity (4.56 nA μM−1). In addition, the OPH/RGO/IL-modified Au electrode displayed good stability and reproducibility.
In this study, the KLN thin films were prepared by RF-magnetron sputtering method onto Coming 1737 glass. The effect of working pressure, substrate temperature, RF-power, sputter gas ratio (Ar/O2) during deposition was investigated. For an optimum deposition condition, the postannealing, RTA(rapid thermal annealing) and IPA(in-situ post annealing)methods were employed. Both RTA and IPA processes, which were conducted at different deposition and annealing temperature influenced surface morphology and optical properties of the films. The films prepared by the IPA process showed a lower crystallization temperature and better optical transmittance.
We report the failure mode observed in polymer EL blue device. Such modes were analyzed by non-destructive and destructive ways. As a non-destructive way, investigation of mobility changes of hole and electron, measuring transient EL corresponding to life curve, had been done. We also observed compositional and morphological variation using TEM-EDX, STM, FT-IR, TOF-SIMS and reverse engineering method as a destructive way. Electron mobility has a higher dependency on life curve, which fact could be reflected on the formation of insoluble layer inside emitting layer on anode side. And such insoluble layer showed relatively ordered surface morphology, and might be a cross-linked layer through C-O-C bond cleavage process while EL operation. But, contrary to sulfur migration mechanism into insoluble layer insisted by CDT, we did confirm no obvious difference of sulfur composition between insoluble and emitting layers. Rather, there's some degree of Ba diffusion into emitting layer from decomposition of BaF2, but, which dose not have a major effect on device degradation.
The low frequency noise of individual ZnO nanowire (NW) field effect transistors (FETs) exposed to air is systematically characterized. The measured noise power spectrum shows a classical 1/f type. The noise amplitude is independent of source-drain current and inversely proportional to gate voltage. The extracted Hooge's constant of ZnO NW is found to be 6.52×10−3. In addition, the low frequency noise of ZnO NW according to NW resistance and contact property are investigated. The noise amplitude is proportional to the square of ZnO NW resistance. If a sample shows a nonlinear current-voltage (I-V) characteristic due to a poor electrical contact, the noise power spectrum is proportional to the third power of current instead of the square of current.
We have investigated temperature dependence on the hysteresis phenomenon of SLS poly-Si TFT on a glass substrate, extremely at low temperature (213K). The p-type sequential lataral solidification (SLS) polycrystalline Silicon (poly-Si) TFT was fabricated on glass substrate. As the temperature was reduced, it was observed that hysteresis phenomenon was increased, whereas the hysteresis was suppressed at high temperature. This could be explained by a difference of initially electron and hole trapped charges into gate insulator is much larger in low temperature than in high temperature. And we have verified that drain current was changed with a different previous gate starting voltage even at same bias condition by experimental results due to the hysteresis phenomenon of SLS poly-Si TFT. Hysteresis of SLS poly-Si TFT should be improved for a pixel element of high quality AMOLED display.
Field effect transistors(FETs) made of ZnO nanowires are very sensitive to the gas environment, so that the passivation can be a good way to get reliable nanowire FETs with longer lifetime and the better mobility. The studies on the passivation effects with the positive electron-beam resist was investigated by selectively covering the part of nanowire devices between the electrodes. Reproducible electrical characteristics were recorded, reflecting the stable electrical properties by the passivation which deters the degradation of a device. Considering the defect states of oxide nanowires dominate the charge states, the pre-state just before the passivation process will be crucial to understand the reproducible and controllable device characteristics of nanowire devices.
A surfactant-assisted co-precipitation method was employed for obtaining high surface area Ni-SDC with improved structural properties for SOFC applications. In the work, a cationic surfactant, cetyltrimethylammonium bromide(CTAB) was employed with NiCl2, SmCl3 and CeCl3 as precursors and NH4OH as mineralizer. The elimination of surfactants upon calcination gives rise to the formation of high surface area NiO-SDC. When calcined at 600°C, the powders with surface area of 249 m2/g, were obtained and the pore size was 14.45 nm. The powders consist of two phases, the cubic NiO and SDC confirmed with X-ray diffraction identification.
Due to a rapid shrinkage in memory devices, backned of the line process experiences great difficulties, especially Al metallization. Furthermore, there is a continuous demands in low line resistance in order to promote device performances. In this article, Al damascene process is proposed as compared to Al patterning process, which suffers from inherent pattering issue at a fine pitch under 70nm. The most difficulties in the development of Al damascene process were to form a stable and void free Al in fine trench and to obtain scratch and corrosions free Al surface. In this study, 50nm beyond fill was successfully achieved by “bottom up growth” of CVD Al. For the process, CVD Al by using Methylpyrroridine Alane (MPA) precursor was deposited on a stacked film of CVD TiN and PVD TiN as a wetting layer, which was followed by PVD Al and reflow, then the Al surface was polished with colloidal silica based slurry.
In addition, electrical property of Al scheme and W scheme was compared with damascene pattern, along with which we demonstrated that around 36% decrease in parasitic capacitance is achievable by decrease of metal line height from 3500A to 1000A on simulation test implying that device performance could be enhanced.
The Cambrian trilobite Shantungia Walcott, 1905 is a monotypic genus, with S. spinifera Walcott, 1905 as the genotype and is characterized by its long frontal spine extending medially from the anterior cranidial border. The genus has hitherto been known restricted in occurrence to the traditional Drepanura Zone of North China (Walcott, 1913; Endo and Resser, 1937; Qiu et al., 1983; Zhang and Jell, 1987). As Drepanura Bergeron, 1899 is preoccupied by a collembolan insect and Neodrepanura Özdikmen, 2006 was proposed as a replacement, this zone is referred to as the Neodrepanura Biozone herein.