| 1. |
- Sun, Yongxin, et al.
(författare)
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Inflammatory markers in matched plasma and cerebrospinal fluid from patients with Alzheimer's disease.
- 2003
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 16:3, s. 136-144
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that a number of molecules associated with inflammation are involved in the pathogenesis of Alzheimer's disease (AD). We measured the levels of alpha1-antichymotrypsin (ACT), alpha1-antitrypsin (AAT), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and oxidised low-density lipoprotein (oxLDL) in matched cerebrospinal fluid (CSF) and plasma of 141 patients with probable AD. We found a significant relationship between CSF and plasma levels of ACT (r = 0.4, p < 0.001), IL-6 (r = 0.74, p < 0.001), MCP-1 (r = 0.71, p < 0.001), and a borderline relationship between CSF and plasma oxLDL (r = 0.22, p < 0.05). In addition, linear regression analysis revealed a positive correlation between levels of CSF-ACT and oxLDL (p < 0.001), but an inverse relation between levels of CSF ACT, CSF AAT and MCP-1 (p < 0.001). A significant correlation was also found between levels of CSF ACT, oxLDL and the ratio of CSF to serum albumin, which is used as a measure of the blood-brain barrier function. Our data extend previous reports regarding the inflammatory markers in the plasma and CSF of patients with AD and provide good evidence that levels of ACT, IL-6, MCP-1 and oxLDL in plasma and CSF might be candidates as biomarkers for monitoring the inflammatory process in AD.
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| 2. |
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| 3. |
- Ning, Yuping, et al.
(författare)
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Effects of substrates, film thickness and temperature on thermal emittance of Mo/substrate deposited by magnetron sputtering
- 2016
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 128, s. 73-79
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Tidskriftsartikel (refereegranskat)abstract
- The thermal emittance of the Mo film, as an IR-refiector in solar selective absorbing coatings, is the most important property. The effects of the substrate material, the substrate surface roughness, the film thickness and the temperature on the thermal emittance of the Mo/substrate have been investigated. A series of Mo films with increasing film thickness were deposited on two types of substrate materials (glass and stainless steel). A saturated Mo thickness of 50 nm is found to produce the lowest thermal emittance. The thermal emittance of the Mo film is reduced by decreasing the substrate surface roughness. The emittance of the optimal Mo film remains 0.05 from 25 degrees C to 400 degrees C, which can meet the optical requirements for the IR-reflector.
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| 4. |
- Ning, Yuping, et al.
(författare)
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Investigation on low thermal emittance of Al films deposited by magnetron sputtering
- 2016
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 75, s. 133-138
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Tidskriftsartikel (refereegranskat)abstract
- A series of Al films with different thicknesses were deposited on polished stainless steel by direct current (DC) magnetron sputtering as a metal IR-reflector layer in solar selective absorbing coating (SSAC). The effects of the film thickness and the temperature on the thermal emittance of the Al films are studied. An optimal thickness 78 nm of the Al film for the lowest total thermal emittance is obtained. The thermal emittance of the optimal Al film keeps close to 0.02 from 25 degrees C to 400 degrees C, which are low enough to satisfy the optical requirements in SSAC. The optical constants of the AI film are deduced by fitting the reflectance and transmission spectra using SCOUT software.
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| 5. |
- Ning, Yuping, et al.
(författare)
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Tuning of reflectance transition position of Al-AlN cermet solar selective absorbing coating by simulating
- 2017
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 80, s. 65-70
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Tidskriftsartikel (refereegranskat)abstract
- The reflectance spectra of the AI/double cermet Al-AIN/AIO(x)N(y) solar selective absorbing coating are simulated. Two methods have been found to effectively tune the position of reflectance transition of the Al-MN cermet solar selective absorbing coating, which is crucial to obtain a low emittance at elevated temperature. The position of reflectance transition is mainly determined by the high metal volume fraction (HMVF) cermet layer. It is effectively tuned to shift to lower wavelength by reducing the metal volume fraction or the thickness of the HMVF layer. This provides easy ways to tune the position of reflectance transition.
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| 6. |
- Sun, Yongxin, et al.
(författare)
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Alpha1-antichymotrypsin/Alzheimer's peptide Abeta(1-42) complex perturbs lipid metabolism and activates transcription factors PPARgamma and NFkappaB in human neuroblastoma (Kelly) cells.
- 2002
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Ingår i: Journal of Neuroscience Research. - : Wiley. - 1097-4547 .- 0360-4012. ; 67:4, s. 511-522
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Tidskriftsartikel (refereegranskat)abstract
- Amyloid-beta peptide (A) and the serpin proteinase inhibitor 1-antichymotrypsin (ACT) are components of the amyloid plaques associated with Alzheimer's disease (AD). A exists in soluble monomeric and oligomeric forms and in an insoluble polymerised fibrillar form, but it is not clear which of these plays the most important role in the etiology of AD. In vitro, A1-42 interacts with ACT, and as a result of this, ACT loses its proteinase inhibitor activity and polymerisation of A1-42 is promoted. Here we provide evidence that new molecular forms resulting from incubation of ACT with A1-42 have multiple cellular level effects on neuronal cells. The mixture of soluble A and an ACT/A complex formed by 2 hr incubation at a 10:1 molar ratio of A:ACT strongly induce cellular proliferation and expression of transcription factors peroxisome proliferator-activated receptor-gamma (PPAR) and NFB, and also increase uptake and depress degradation of native and oxidised low-density lipoprotein (LDL) by cells. Similar but less pronounced effects are seen when cells are exposed to the A peptide alone preincubated for 2 hr. A1-42 and to a lesser extent ACT/A1-42 complex mixture prepared by 2 hr incubation both inhibit association of native LDL with cells. Neither ACT alone nor the A1-42 and ACT/A1-42 forms prepared by 24-hr incubation show any significant effects in these assays. We propose that specific molecular forms of A1-42 and ACT/A1-42 complex mixture, both dependent on the abundances of A1-42 and ACT/A1-42 in vivo and on their time of exposure to each other, have cellular effects which are important for the initiation and progression of the pathologies associated with AD.
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| 7. |
- Sun, Yongxin
(författare)
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Alzheimer's Disease: The role of alpha1-antichymotrypsin-amyloid peptide (Abeta 1-42) interaction in the pathogenesis of Alzheimer's disease
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Alzheimer’s disease (AD) is an age-related, irreversible brain disorder that occurs gradually and results in memory loss, behavioural and personality changes. The disease is characterized by an abnormal accumulation of amyloid-beta (Ab) peptide in the extracellular space and the protein Tau within nerve cells of certain regions of the brain. Aâ1-42 is a major component of amyloid deposits in AD, but other molecules related to inflammation, such as proteases and their inhibitors, proteoglycans, cytokines and extracellular matrix proteins, are also co-localized. In addition, the activated glia is shown to surround the amyloid core, indicating the presence of inflammation in AD brains. á1-antichymotrypsin (ACT) is an acute phase reactant that belongs to the family of serine protease inhibitors and is specifically found to interact with Aâ1-42 and be present in amyloid deposits in AD brain. We studied the interaction between Aâ1-42 and ACT, and the biological activities of Aâ1-42/ACT complex mixture on cellular lipid metabolism, cytokine release and expression of nuclear transcription factors, in vitro. Our data show that the Aâ1-42/ACT complex mixture induces more profound intracellular accumulation of native and oxidised LDL in human neuroblastoma (Kelly) cells and stimulates a larger release of TNFá in human glioma (DK-MG) cells, compared to Aâ1-42 peptide alone. Moreover, Aâ1-42/ACT complex mixture was found to activate more strongly inflammation-related transcription factors peroxisome proliferator-activated receptor-ã and nuclear factor-êB than Aâ1-42. Findings that pre-treatment of glioma cells with pravastatin diminished or totally suppressed the capacity of soluble Ab1-42 to induce gelatinase B, interleukin-6 and free radical generation allowed us to propose that, the observed effects of pravastatin may be what contribute to its beneficial anti-inflammatory properties described, in vivo. By analyzing biomarkers related to inflammation in plasma and matched cerebrospinal fluid (CSF) from patients with probable AD, we found a positive correlation between plasma and CSF levels of ACT, IL-6, MCP-1 and oxLDL, indicating that the plasma levels and certain combinations of these biomarkers may provide good possibilities to describe the disease status in Alzheimer’s patients. Our data support the hypothesis that the interactions between Aâ1-42 and ACT, or Aâ1-42 and other molecules present in amyloid deposits, may have an important effect on the chronic inflammatory process present in AD, in vivo, and could be used as markers to evaluate the progression of the disease.
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| 8. |
- Sun, Yongxin, et al.
(författare)
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Glioma cell activation by Alzheimer's peptide Abeta1-42, alpha1-antichymotrypsin, and their mixture.
- 2002
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Ingår i: Cellular and Molecular Life Sciences. - 1420-9071. ; 59:10, s. 43-1734
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Tidskriftsartikel (refereegranskat)abstract
- We compared the effects of Alzheimer’s peptide (Ab1–42), a1-antichymotrypsin (ACT) and an ACT/Ab1–42 mixture on human glioma DK-MG cells. The solution of Ab (5 mM) formed by 2-h incubation at room temperature induced tumour necrosis factor-a (TNF-a) and interleukin (IL)-6 levels by 55 and 45%, respectively, and increased gelatinase B activity by 67%, while exposure of cells to the ACT/Ab1–42 mixture (1:10 molar ratio ACT: Ab1–42) under the same experimental conditions showed no effect on IL-6 levels or gelatinase B activity, but strongly induced TNF-a (by 190%), compared to the con- CMLS, Cell. Mol. Life Sci. 59 (2002) 1734–1743 1420-682X/02/101734-11 © Birkhäuser Verlag, Basel, 2002 CMLS Cellular and Molecular Life Sciences trols. Stimulation of the cells with Ab1–42 alone, but not with ACT, increased by about 20% low-density lipoprotein (LDL) uptake and mRNA levels for LDL receptor and HMG-CoA reductase, while the ACT/Ab1–42 mixture significantly increased LDL uptake (by 50%), up-regulated mRNA levels for LDL receptor and HMG-CoA reductase by 48 and 63%, respectively, and increased lipid accumulation by about 20-fold. These data suggest a possible new role for Ab in Alzheimer’s disease through its interaction with the inflammatory reactant, ACT.
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| 9. |
- Sun, Yongxin, et al.
(författare)
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Pravastatin inhibits pro-inflammatory effects of Alzheimer's peptide Abeta(1-42) in glioma cell culture in vitro.
- 2003
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Ingår i: Pharmacological Research. - 1096-1186 .- 1043-6618. ; 47:2, s. 119-126
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Tidskriftsartikel (refereegranskat)abstract
- Statins are known to exert a number of biological effects apart from reducing cholesterol synthesis. The results of recent studies indicate that patients treated with pravastatin have a lower prevalence of diagnosed Alzheimer’s disease (AD). These observations prompted us to examine the effects of pravastatin on Alzheimer’s peptide (Aβ1–42)-induced pro-inflammatory activation in the human glioma cell line in vitro. Cells alone or cells pre-treated with pravastatin (0.1 mg ml−1) for 24 h were stimulated with 5 μM of freshly dissolved Aβ1–42 for the next 24 h. The pre-treatment of cells with pravastatin diminished the capacity of Aβ to induce metalloproteinases, cytokine IL-6 and free radical levels. Although both pravastatin and Aβ1–42 separately increased PPARγ activity, the combination of Aβ1–42 and pravastatin resulted in no effect on PPARγ expression. These data indicate that soluble forms of Aβ1–42, which are a potent stimulus of pro-inflammatory activation of glioma cells in vitro, could be a good target for pravastatin.
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| 10. |
- Wu, Yongxin, et al.
(författare)
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Optical simulation and experimental optimization of Al/NbMoN/NbMoON/SiO2 solar selective absorbing coatings
- 2015
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Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 134, s. 373-380
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Tidskriftsartikel (refereegranskat)abstract
- For the applications in solar thermal power, the preparation and optimization of an Al/NbMoN/NbMoON/SiO2 multilayer solar selective absorbing coating are carried out by combining experiments with optical simulation. A series of NbMoN and NbMoON single layers are deposited by magnetron reactive sputtering method with different N-2/O-2 gas flowing rates. And then their optical constants are obtained by fitting their reflection (R) and transmission (T) spectra in the wavelength range of 300-2500 nm using SCOUT software. These optical constants are used to design the Al/NbMoN/NbMoON/SiO2 solar selective absorbing coating so as to get the ideal spectral selectivity, i.e. high alpha/epsilon ratio. According to the optical design of the coating structure, we prepared the all-layer coating, and the thickness of each layer was optimized until the best spectral selective properties are obtained. The experimental reflectance spectrum fits very well with the simulated result. The optimized solar absorbing coating deposited on stainless steel substrate exhibited high absorptance (alpha=0.948) and low emittance (epsilon=0.050) at 80 degrees C. It offers a good method to quickly reach the ideal spectral selectivity through optical simulation. The thermal stability of the coating is evaluated, and it exhibits a good thermal stability in vacuum at 400 degrees C.
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| 11. |
- Wu, Yongxin, et al.
(författare)
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Study on the thermal stability of Al/NbTiSiN/NbTiSiON/SiO2 solar selective absorbing coating
- 2015
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Ingår i: Solar Energy. - : Elsevier BV. - 0038-092X .- 1471-1257. ; 119, s. 18-28
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the NbTiSiN and NbTiSiON layers are used instead of NbTiN and NbTiON layers to further improve the thermal stability of Al/NbTiN/NbTiON/SiO2 multilayer solar selective absorbing coating. The thermal stability of Si-doped individual layers and multilayer coatings are investigated. The X-ray diffraction (XRD) results show that Si incorporation into NbTiN (NbTiSiN) layer does not change its preferred orientation, and the Si-doped NbTiON (NbTiSiON) layer remains in amorphous phase. On the other hand, by introducing Si into NbTiN and NbTiON layers induce significant improvement of the oxidation resistance at 500 degrees C in air. After ageing in air at 500 degrees C for 2 h, the absorptance and emittance (at 400 degrees C) of Al/NbTiN/NbTiON/SiO2 and Al/NbTiSiN/NbTiSiON/SiO2 multilayer coatings change from 0.934/0.13 and 0.931/0.12 to 0.538/0.14 and 0.922/0.13, respectively. Meanwhile the surface roughness increases from 18.3 and 7.9 to 41.5 and 14.7 respectively, as atomic force microscopy (AFM) shows. The Al/NbTiSiN/NbTiSiON/SiO2 coating still has a high absorptance (0.910) and low emittance (0.13, at 400 degrees C) after ageing at 550 degrees C in vacuum for 100 h. It displays that Si-doping play an important role in the improvement of the thermal stability.
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