| 1. |
- Liu, Jin-ming, et al.
(författare)
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Mid-term effects of lung volume reduction surgery on pulmonary function in patients with chronic obstructive pulmonary disease
- 2007
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Ingår i: Chinese Medical Journal. - 0366-6999. ; 120:8, s. 658-662
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Tidskriftsartikel (refereegranskat)abstract
- Background Now lung volume reduction surgery (LVRS) has become one of the most effective methods for the management of some cases of severe chronic obstructive pulmonary disease (COPD). We evaluated the mid-term effects of LVRS on pulmonary function in patients with severe COPD. Methods Ten male patients with severe COPD aged 38-70 years underwent LVRS and their pulmonary function was assessed before, 3 months and 3 years after surgery. The spirometric and gas exchange parameters included residual volume, total lung capacity, inspiratory capacity, forced vital capacity, forced expiratory volume in one second, diffusion capacity for CO, and arterial blood gas. A 6-minute walk distance (6MWD) test was performed. Results As to preoperative assessment, most spirometric parameters and 6MWD were significantly improved after 3 months and slightly 3 years after LVRS. Gas exchange parameters were significantly improved 3 months after surgery, but returned to the preoperative levels after 3 years. Conclusions LVRS may significantly improve pulmonary function in patients with severe COPD indicating for LVRS. Mid-term pulmonary function 3 years after surgery can be decreased to the level at 3 months after surgery. Three years after LVRS, lung volume and pulmonary ventilation function can be significantly improved, but the improvement in gas exchange function was not significant.
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| 2. |
- Fu, Ying, et al.
(författare)
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Nonperturbative dynamic photon absorption of quantum wells
- 2006
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 99:10
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Tidskriftsartikel (refereegranskat)abstract
- Optical photoresponse of quantum wells in the nonperturbative regime has been studied by high-power and ultrafast-oscillating free-electron laser (FEL) experiments, which revealed a profound deviation of the nonlinear power from conventional perturbative multiple photon absorption processes. By combining the experimental and theoretical works we have shown that the nonperturbative solution of the time-dependent Schrodinger equation is essential to understand the experimental observations. Optical transitions of electrons are dynamic. One photon is absorbed or emitted when an electron transits from one electron state to the other. The rates of absorption and emission are proportional to the time interval in the femtosecond time scale. In the picosecond time scale, multiphoton processes emerge. The strong and fast-oscillating FEL source intensifies the dynamic photon absorption and emission processes in the quantum wells, resulting in a much enhanced nonlinearity in the photoresponse spectrum.
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| 3. |
- Jiang, Jun, et al.
(författare)
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Ab initio study of energy band structures of GaAs nanoclusters
- 2009
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 94:9
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Tidskriftsartikel (refereegranskat)abstract
- Electronic states and optical transitions of hydrogen terminated GaAs nanoclusters up to 16.9 nm in diameter were studied using a large-scale quantum chemistry approach called central insertion scheme by which the quantum confinement effect is shown to quantitatively agree with experimental results. The ab initio study further reveals that the effective mass of the conduction-band electron (valence-band hole) in the GaAs nanocluster is larger (smaller) than the bulk material value.
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| 4. |
- Jiang, Jing-Ting, et al.
(författare)
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Lipids changes in liver cancer
- 2007
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Ingår i: Journal of Zhejiang University-Science B. - 1862-1783. ; 8:6, s. 398-409
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Forskningsöversikt (refereegranskat)abstract
- Liver is one of the most important organs in energy metabolism. Most plasma apolipoproteins and endogenous lipids and lipoproteins are synthesized in the liver. It depends on the integrity of liver cellular function, which ensures homeostasis of lipid and lipoprotein metabolism. When liver cancer occurs, these processes are impaired and the plasma lipid and lipoprotein patterns may be changed. Liver cancer is the fifth common malignant tumor worldwide, and is closely related to the infections of hepatitis B virus (HBV) and hepatitis C virus (HCV). HBV and HCV infections are quite common in China and other Southeast Asian countries. In addition, liver cancer is often followed by a procession of chronic hepatitis or cirrhosis, so that hepatic function is damaged obviously on these bases, which may significantly influence lipid and lipoprotein metabolism in vivo. In this review we summarize the clinical significance of lipid and lipoprotein metabolism under liver cancer.
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| 5. |
- Li, N., et al.
(författare)
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Detection wavelengths and photocurrents of very long wavelength quantum-well infrared photodetectors
- 2005
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Ingår i: Infrared Physics and Technology. - : Elsevier BV. - 1350-4495. ; 47:1-2, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- Based on detailed studies of the energy band structure and the optical transitions in very long wavelength (>14 μm) GaAs/AlGaAs quantum-well (QW) infrared photodetectors (QWIPs), we have built a practical QWIP model. We study the factors that determine photogenerated carriers and response wavelengths of photocurrents of very long wavelength QWIPs. The material structures of QWIPs are first characterized by the photoluminescence measurements (PL) at room temperature and 77 K respectively. We have found and confirmed a distinctive difference between photocurrent of QWIPs with only one confined state in the quantum well (QW) and those binding two confined states, which resulted in different dependence of detection wavelength on the quantum well width. Also, we have investigated the dependence of response wavelength on several other parameters for very long wavelength QWIPs, such as barrier width and Al mole fraction. By calculating the density of photogenerated carriers in the continuum above the energy barriers using the PL calibrated QWIP structures, we have demonstrated that due to the high sample quality, the photocarriers can be either in miniband states (Bloch states in the multiple quantum wells), or they transport from one quantum well to the next in the form of propagating waves. We have further calculated the densities of photocarriers in the QWIPs reported in the literature. It is shown that the Bloch wave boundary conditions are appropriate for QWIPs with narrow QWs, whereas propagating wave boundary conditions are appropriate for wide QWs.
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| 6. |
- Tian, Yu-Peng, et al.
(författare)
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Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
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Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
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Tidskriftsartikel (refereegranskat)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
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| 7. |
- Tian, Yu-peng, et al.
(författare)
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Synthesis, crystal structure and NLO properties of a novel ruthenium(II) complex with unusual coordination mode
- 2005
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Ingår i: Transition metal chemistry (Weinheim). - : Kluwer Academic Publishers. - 0340-4285 .- 1572-901X. ; 30:7, s. 778-785
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Tidskriftsartikel (refereegranskat)abstract
- A new Schiff base 4-[N-hydroxyethyl-N-(methyl)amino]benzaldehyde S-methyl dithiocarbazate (HL, where H is a dissociable proton) and the ruthenium complex [Ru(bpy)2L]PF6 (bpy = 2,2′-bipyridine) have been synthesized. The structural determinations of the ligand and its ruthenium complex, by X-ray crystallography, show that the ligand is coordinated as a monoanionic bidentate N, S-donor, forming a four-member chelate ring with a bite angle of 65.91°. The complex shows intense MLCT transitions in the visible region. Fluorescent and electrochemical properties have been also studied. The complex in DMF solution exhibited a strong two-photon absorption (t.p.a.) at 532 nm nanosecond laser pulses. The t.p.a. coefficient β, t.p.a. cross-section σ and the third-order optical nonlinearity χ(3) of the complex and the ligand have been determined by the Z-scan technique.
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| 8. |
- Xiao, Kai, et al.
(författare)
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Photoelectrical characteristics of a C/CNx multiwalled nanotube
- 2007
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 17:15, s. 2842-2846
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Tidskriftsartikel (refereegranskat)abstract
- A nanotube diode fabricated from a single C/CNx multiwalled nanotube exhibits a large photocurrent and a large photovoltage under illumination. The current-voltage (I-V) characteristics of the diode indicate a clear rectification effect. By comparing the I-V characteristics of C, CNx, and C/CNx nanotube diodes, we show that the rectifying characteristics of the C/CNx diode arises from the molecular junction formed at the C/CNx interface where the C and CNx segments are chemically bonded. External radiation photochernically generates electrons and holes in the C/CNx nanotube, producing a large photocurrent because of the influence of the strong electric field in the vicinity of the C/CNx junction. These unique photoresponsive characteristics of C/CNx, nanotube junction diodes points to potential applications such as photovoltaic devices and photodiodes.
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| 9. |
- Yang, Ying, et al.
(författare)
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Beneficial effect of rosuvastatin on cardiac dysfunction is associated with alterations in calcium-regulatory proteins.
- 2009
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Ingår i: European journal of heart failure : journal of the Working Group on Heart Failure of the European Society of Cardiology. - : Wiley. - 1388-9842. ; 11:1, s. 6-13
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: The normal expression of Ca(2+)-regulatory protein is critical for efficient myocardial function. The present study tested the hypothesis that rosuvastatin treatment may attenuate left ventricular (LV) remodelling and dysfunction in the failing heart, which may be associated with alterations of Ca(2+)-regulatory protein. METHODS AND RESULTS: We investigated the change of LV remodelling and function in a rat model of cardiac dysfunction due to myocardial infarction (MI) with or without rosuvastatin (10 mg/kg/day) treatment for 10 weeks. The protein expression of sarcoplasmic reticulum Ca(2+) ATPase (SERCA)2a, phospholamban (PLB), and phospho-PLB at serine-16 (pSer16-PLB), as well as SERCA activity, interleukin (IL)-6, and IL-10 levels were evaluated. After rosuvastatin treatment, LV remodelling and dysfunction were prevented. Rosuvastatin prevented the decrease of SERCA2a and pSer16-PLB expression, increased SERCA activity, but showed no effect on PLB expression. Furthermore, rosuvastatin reduced the increased IL-6 level and further elevated IL-10 level in the peri-infarct and remote zones of MI. Serum lipid levels remained unchanged. CONCLUSION: Rosuvastatin is effective in preventing LV remodelling and dysfunction in the failing heart. The molecular mechanism may be related to normalization of SERCA2a expression, SERCA activity, and pSer16-PLB levels, as well as through cytokine alterations independent of its lipid-lowering effect.
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| 10. |
- Zhang, Shuai, et al.
(författare)
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Ultrawideband MIMO/Diversity Antennas With a Tree-Like Structure to Enhance Wideband Isolation
- 2009
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Ingår i: IEEE Antennas and Wireless Propagation Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1536-1225 .- 1548-5757. ; 8, s. 1279-1282
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Tidskriftsartikel (refereegranskat)abstract
- A compact printed ultrawideband (UWB) multiple-input-multiple- output (MIMO)/diversity antenna system (of two elements) with a size of 35 40 mm operating at a frequency range of 3.1-10.6 GHz is proposed. The wideband isolation can be achieved through a tree-like structure on the ground plane. The effectiveness of the tree-like structure is analyzed. Measured S-parameters show that the isolation is better than 16 dB (20 dB in most of the band) across the UWB of 3.1-10.6 GHz. The radiation patterns, gain, and envelope correlation coefficient are also measured. The proposed antenna is suitable for some portable MIMO/diversity applications.
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