| 1. |
- Aamodt, K., et al.
(författare)
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The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
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| 3. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 4. |
- Zeng, Qiao-Shi, et al.
(författare)
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Substitutional alloy of Ce and Al
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:8, s. 2515-2518
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Tidskriftsartikel (refereegranskat)abstract
- The formation of substitutional alloys has been restricted to elements with similar atomic radii and electronegativity. Using high-pressure at 298 K, we synthesized a face-centered cubic disordered alloy of highly dissimilar elements (large Ce and small Al atoms) by compressing the Ce3Al intermetallic compound > 15 GPa or the Ce3Al metallic glass > 25 GPa. Synchrotron X-ray diffraction, Ce L-3-edge absorption spectroscopy, and ab initio calculations revealed that the pressure-induced Kondo volume collapse and 4f electron delocalization of Ce reduced the differences between Ce and Al and brought them within the Hume-Rothery (HR) limit for substitutional alloying. The alloy remained after complete release of pressure, which was also accompanied by the transformation of Ce back to its ambient 4f electron localized state and reversal of the Kondo volume collapse, resulting in a non-HR alloy at ambient conditions.
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| 5. |
- Ding, Yang, et al.
(författare)
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Structural phase transition of vanadium at 69 GPa
- 2007
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 98:8
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Tidskriftsartikel (refereegranskat)abstract
- A phase transition was observed at 63-69 GPa and room temperature in vanadium with synchrotron x-ray diffraction. The transition is characterized as a rhombohedral lattice distortion of the body-centered-cubic vanadium without a discontinuity in the pressure-volume data, thus representing a novel type of transition that has never been observed in elements. Instead of driven by the conventional s-d electronic transition mechanism, the phase transition could be associated with the softening of C-44 trigonal elasticity tensor that originates from the combination of Fermi surface nesting, band Jahn-Teller distortion, and electronic topological transition.
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| 6. |
- Li, Yang, et al.
(författare)
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VEGF-B inhibits apoptosis via VEGFR-1-mediated suppression of the expression of BH3-only protein genes in mice and rats.
- 2008
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Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 118:3, s. 913-923
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Tidskriftsartikel (refereegranskat)abstract
- Despite its early discovery and high sequence homology to the other VEGF family members, the biological functions of VEGF-B remain poorly understood. We revealed here a novel function for VEGF-B as a potent inhibitor of apoptosis. Using gene expression profiling of mouse primary aortic smooth muscle cells, and confirming the results by real-time PCR using mouse and rat cell lines, we showed that VEGF-B inhibited the expression of genes encoding the proapoptotic BH3-only proteins and other apoptosis- and cell death-related proteins, including p53 and members of the caspase family, via activation of VEGFR-1. Consistent with this, VEGF-B treatment rescued neurons from apoptosis in the retina and brain in mouse models of ocular neurodegenerative disorders and stroke, respectively. Interestingly, VEGF-B treatment at the dose effective for neuronal survival did not cause retinal neovascularization, suggesting that VEGF-B is the first member of the VEGF family that has a potent antiapoptotic effect while lacking a general angiogenic activity. These findings indicate that VEGF-B may potentially offer a new therapeutic option for the treatment of neurodegenerative diseases.
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| 7. |
- 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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| 8. |
- Luo, Wei, et al.
(författare)
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Unusual lattice dynamics of vanadium under high pressure
- 2007
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 104:42, s. 16428-16431
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structures and lattice dynamics of pressure-induced complex phase transitions [bcc -> hRl(110.5 degrees) -> distorted-hRl(108.2') -> bcc] in vanadium as a function of pressure up to 400 GPa have been investigated with an ab initio method using density functional perturbation theory (DFPT). At ambient pressure, the soft transverse acoustic phonon mode corresponding to Kohn anomaly appears at a wave vector q = 2k(F) along [xi 00] Gamma -> H high symmetry direction. The nonclegenerate transverse acoustic branches TA(1) on < 110 > and TA(2) on < 001 > show an exceptionally large split at high symmetry point N (0.5 0.5 0.0). The lattice dynamical instability starts at a pressure of 62 GPa (V/V-0 = 0.78, where V-0 is experimental volume of bcc-V at ambient conditions), derived by phonon softening that results in phase transition of bcc -> hR1 (alpha = 110.5 degrees). At compression around 130 GPa (V/V-0 = 0.67), the rhombohedral angle of hR1 phase changed to 108.2 degrees, and the electronic structure changed drastically. At even higher pressure, approximate to 250 GPa (V/V-0 = 0.57), lattice dynamic calculations show that the bcc structure becomes stable again.
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| 9. |
- Wang, Weilong, 1978-, et al.
(författare)
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Enhanced thermal conductivity and thermal performance of form-stable composite phase change materials by using beta-Aluminum nitride
- 2009
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 86:7-8, s. 1196-1200
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Tidskriftsartikel (refereegranskat)abstract
- beta-Aluminum nitride powder is a promising additive due to its great conductivity value, which can enhance the thermal conductivity of organic phase change materials. In this paper, a high conductivity form-stable phase change material was prepared by blending polyethylene glycol, silica gel, and P-Aluminum nitride powder. The conductivity value of the composite PCMs was determined using the Hotdisk thermal analyzer, which is based on the transient plane source technique. Experiment of heat storage and release performance was carried out to investigate heat efficiencies of TES system. The results showed that thermal conductivity of composite PCMs increased with an increase in beta-Aluminum nitride content, but the value of latent heat decreased correspondingly. There was no change on the melting temperature while different ratios of composites. The value of thermal conductivity changed from 0.3847 W m(-1) K-1 to 0.7661 W m(-1) K-1 with the increase of mass ratio of beta-Aluminum nitride from 5% to 30%. The heat storage and release rate of the composite PCMs was higher than that of pure polyethylene glycol. Crown
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| 10. |
- Wang, Weilong, 1978-, et al.
(författare)
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Preparation and performance of form-stable polyethylene glycol/silicon dioxide composites as solid–liquid phase change materials
- 2009
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 86:2, s. 170-174
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Tidskriftsartikel (refereegranskat)abstract
- This work mainly involved the preparation and characterization of form-stable polyethylene glycol (PEG)/silicon dioxide (SiO2) composite as a novel solid–liquid phase change material (PCM). In this study, the polyethylene glycol/silicon dioxide composites as form-stable, solid–liquid phase change material (PCM) was prepared. In this new material, the polyethylene glycol acts as the latent heat storage material and silicon dioxide serves as the supporting material, which provides structural strength and prevents the leakage of the melted polyethylene glycol. Results indicated that the composite remained solid when the weight percentage of silicon dioxide was higher than 15%. Moreover, the polyethylene glycol was observed to disperse into the network of the solid silicon dioxide by investigation of the structure of the composite PCMs using a scanning electronic microscope (SEM). The properties of the porous materials and phase change materials were characterized using Fourier transformation infrared spectroscope (FTIR). The transition process was observed using polarizing optical microscope (POM) and dynamic thermo mechanic analysis (DMA). The melting temperatures and latent heats of the form-stable PEG/SiO2 composite PCMs were determined using differential scanning calorimeter (DSC).
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| 11. |
- Wang, Weilong, 1978-, et al.
(författare)
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Preparation and thermal properties of polyethylene glycol/expanded graphite blends for energy storage
- 2009
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 86:9, s. 1479-1483
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Tidskriftsartikel (refereegranskat)abstract
- Expanded graphite is a promising heat transfer promoter due to its high conductivity, which improves the thermal conductivity of organic phase change materials. Moreover, it can also serve as supporting materials to keep the shape of the blends stable during the phase transition. After various investigation, the results showed that the maximum weight percentage of polyethylene glycol was as high as 90% in this paper without any leakage during the melting period, with the latent heat of 161.2 J g(-1) and the melting point of 61.46 degrees C. It was found that the value of the latent heat was related to the polyethylene glycol portion, increased with the increase in polyethylene glycol content. Moreover, the measured enthalpy of the composite phase change materials was proportional to the mass ratio of the polyethylene glycol component. The melting temperatures were almost the same with different ratios of composites. The conductivity of blends was improved significantly with the high value of 1.324 W m(-1) K-1 compared to the pure polyethylene glycol conductivity of 0.2985 W m(-1) K-1.
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| 12. |
- Yoo, S. J. B., et al.
(författare)
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Spectral phase encoded time spread optical code division multiple access technology for next generation communication networks Invited
- 2007
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Ingår i: Journal of Optical Networking. - 1536-5379. ; 6:10, s. 1210-1227
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Tidskriftsartikel (refereegranskat)abstract
- We overview and summarize the progress of the spectral phase encoded time spreading (SPECTS) optical code division multiple access (O-CDMA) technology. Recent progress included a demonstration of a 320 Gbit/s (32-user x 10 Gbit/s) all-optical passive optical network testbed based on the SPECTS O-CDMA technology and a theoretical prediction of the spectral efficiency at 100% and above. In particular, InP-based integrated photonics allows implementation of SPECTS O-CDMA transmitters and receivers monolithically integrated on a chip. The integrated InP chip technology not only allows robust and compact configurations for practical and low-cost O-CDMA network deployments but also offers code reconfigurations at rapid rates for secure communication applications.
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| 13. |
- Zhang, Fan, et al.
(författare)
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VEGF-B is dispensable for blood vessel growth but critical for their survival, and VEGF-B targeting inhibits pathological angiogenesis
- 2009
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:15, s. 6152-6157
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Tidskriftsartikel (refereegranskat)abstract
- VEGF-B, a homolog of VEGF discovered a long time ago, has not been considered an important target in antiangiogenic therapy. Instead, it has received little attention from the field. In this study, using different animal models and multiple types of vascular cells, we revealed that although VEGF-B is dispensable for blood vessel growth, it is critical for their survival. Importantly, the survival effect of VEGF-B is not only on vascular endothelial cells, but also on pericytes, smooth muscle cells, and vascular stem/progenitor cells. In vivo, VEGF-B targeting inhibited both choroidal and retinal neovascularization. Mechanistically, we found that the vascular survival effect of VEGF-B is achieved by regulating the expression of many vascular prosurvival genes via both NP-1 and VEGFR-1. Our work thus indicates that the function of VEGF-B in the vascular system is to act as a "survival," rather than an "angiogenic" factor and that VEGF-B inhibition may offer new therapeutic opportunities to treat neovascular diseases.
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