| 1. |
- Ablikim, M., et al.
(författare)
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Measurements of (XcJ)-> K+K-K+K- decays
- 2006
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 642:3, s. 197-202
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Tidskriftsartikel (refereegranskat)abstract
- Using 14M psi(2S) events taken with the BESII detector, chi(cJ) -> 2(K+K-) decays are studied. For the four-kaon final state, the branching fractions are B(chi(c0,1,2) ->.2(K+K-)) = (3.48 +/- 0.23 +/- 0.47) x 10(-3), (0.70 +/- 0.13 +/- 0.10) x 10(-3), and (2.17 +/- 0.20 +/- 0.31) x 10(-3). For the phi K+K- final state, the branching fractions, which are measured for the first time, are B(chi(c0,1,2) -> phi K+K-) = (1.03 +/- 0.22 +/- 0.15) x 10(-3), (0.46 +/- 0.16 +/- 0.06) x 10(-3), and (1.67 +/- 0.26 +/- 0.24) x 10(-4). For the phi phi final state, B(chi(c0,2) -> phi phi) = (0.94 +/- 0.21 +/- 0.13) x 10(-3) and (1.70 +/- 0.30 +/- 0.25) x 10(-3).
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| 2. |
- Liu, Wennuan, et al.
(författare)
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Association of a germ-line copy number variation at 2p24.3 and risk for aggressive prostate cancer.
- 2009
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Ingår i: Cancer research. - 1538-7445. ; 69:6, s. 2176-9
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Tidskriftsartikel (refereegranskat)abstract
- We searched for deletions in the germ-line genome among 498 aggressive prostate cancer cases and 494 controls from a population-based study in Sweden [CAncer of the Prostate in Sweden (CAPS)] using Affymetrix SNP arrays. By comparing allele intensities of approximately 500,000 SNP probes across the genome, a germ-line deletion at 2p24.3 was observed to be significantly more common in cases (12.63%) than in controls (8.28%); P = 0.028. To confirm the association, we genotyped this germ-line copy number variation (CNV) in additional subjects from CAPS and from Johns Hopkins Hospital (JHH). Overall, among 4,314 cases and 2,176 controls examined, the CNV was significantly associated with prostate cancer risk [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.06-1.48; P = 0.009]. More importantly, the association was stronger for aggressive prostate cancer (OR, 1.31; 95% CI, 1.08-1.58; P = 0.006) than for nonaggressive prostate cancer (OR, 1.19; 95% CI, 0.98-1.45; P = 0.08). The biological effect of this germ-line CNV is unknown because no known gene resides in the deletion. Results from this study represent the first novel germ-line CNV that was identified from a genome-wide search and was significantly, but moderately, associated with prostate cancer risk. Additional confirmation of this association and functional studies are warranted.
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| 3. |
- Sun, Jielin, et al.
(författare)
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Evidence for two independent prostate cancer risk-associated loci in the HNF1B gene at 17q12
- 2008
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Ingår i: Nature Genetics. - London : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 40:10, s. 1153-1155
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We carried out a fine-mapping study in the HNF1B gene at 17q12 in two study populations and identified a second locus associated with prostate cancer risk, 26 kb centromeric to the first known locus (rs4430796); these loci are separated by a recombination hot spot. We confirmed the association with a SNP in the second locus (rs11649743) in five additional populations, with P = 1.7 10-9 for an allelic test of the seven studies combined. The association at each SNP remained significant after adjustment for the other SNP.
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| 4. |
- Sun, Shiguo, et al.
(författare)
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Study of Highly Efficient Bimetallic Ruthenium Tris-bipyridyl ECL Labels for Coreactant System
- 2009
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 81:24, s. 10227-10231
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Tidskriftsartikel (refereegranskat)abstract
- A series of bimetallic ruthenium complexes [(bpy)(2)Ru(bpy)(CH2)(n)(bpy)Ru(bpy)(2)](4+) (1, where bpy is 2,2'-bipyridinyl, n = 3, 5, 8) for the coreactant electrochemiluminescence (ECL) system have been synthesized. Their ECL property at different working electrode has been studied in 0.1 M phosphate buffer by using tripropylamine (TPrA) and 2-(dibutylamino) ethanol (DBAE) as the coreactant. The results demonstrate that the ECL intensity depends largely on the length of the saturated carbon chain linkage: the longer is the carbon chain, the higher is the ECL intensity. A remarkable ECL enhancement (up to about 25 times), in comparison with the commonly used metallic [Ru(bpy)(3)](2+), has been observed from 1c (n = 8) at Pt electrode. With 20 mM TPrA, the log of the ECL intensity increases linearly with the log of complex 1c concentrations over the concentration range of 1.0 x 10(-16) to 1.0 x 10(-6) M at glassy carbon electrode. The detection limit is 1.0 x 10(-16) M at a signal-to-noise ratio of 3. This is the highest ECL detection limit for bimetallic system reported until now. The study provides a general methodology to further improve and tune the ECL efficiency by using multimetallic ruthenium complexes.
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| 5. |
- Zhang, Tongyan, et al.
(författare)
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Redox-induced partner radical formation and its dynamic balance with radical dimer in cucurbit 8 uril
- 2009
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 11:47, s. 11134-11139
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Tidskriftsartikel (refereegranskat)abstract
- N-(4-Hydroxy-phenoxyethyl)-N'-ethyl-4,4'-bipyridium (1) can form a stable 1 : 1 inclusion complex with CB[8] in aqueous solution, in which the hydroxyphenol (HP) moiety is back-folded and inserted together with the viologen moiety into the cavity of CB[8]. When the ethyl viologen dication (EV2+) in 1 is reduced, chemically or electrochemically, an intramolecular partner radical (EV+center dot-HP)/CB[8] can be detected, meanwhile, a dynamic balance between the partner radical and the intermolecular radical dimer (EV+center dot-HP)(2)/CB[8] can be observed.
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| 6. |
- Dong, Jin Song, et al.
(författare)
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Timed Automata Patterns
- 2008
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Ingår i: IEEE Transactions on Software Engineering. - 0098-5589 .- 1939-3520. ; 34:6, s. 844-859
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Hsu, Fang-Chi, et al.
(författare)
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A novel prostate cancer susceptibility locus at 19q13.
- 2009
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Ingår i: Cancer research. - 1538-7445. ; 69:7, s. 2720-3
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Tidskriftsartikel (refereegranskat)abstract
- A two-stage genome-wide association study (GWAS) of the Cancer Genetic Markers of Susceptibility (CGEMS) initiative identified single nucleotide polymorphisms (SNP) in 150 regions across the genome that may be associated with prostate cancer (PCa) risk. We filtered these results to identify 43 independent SNPs where the frequency of the risk allele was consistently higher in cases than in controls in each of the five CGEMS study populations. Genotype information for 22 of these 43 SNPs was obtained either directly by genotyping or indirectly by imputation in our PCa GWAS of 500 cases and 500 controls selected from a population-based case-control study in Sweden [Cancer of the Prostate in Sweden (CAPS)]. Two of these 22 SNPs were significantly associated with PCa risk (P<0.05). We then genotyped these two SNPs in the remaining cases (n=2,393) and controls (n=1,222) from CAPS and found that rs887391 at 19q13 was highly associated with PCa risk (P=9.4 x 10(-4)). A similar trend of association was found for this SNP in a case-control study from Johns Hopkins Hospital (JHH), albeit the result was not statistically significant. Altogether, the frequency of the risk allele of rs887391 was consistently higher in cases than controls among each of seven study populations examined, with an overall P=3.2 x 10(-7) from a combined allelic test. A fine-mapping study in a 110-kb region at 19q13 among CAPS and JHH study populations revealed that rs887391 was the most strongly associated SNP in the region. Additional confirmation studies of this region are warranted.
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| 8. |
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| 9. |
- Keita, Asa V., et al.
(författare)
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Effects of chronic stress on the immune response to oral human serum albumin-conjugated starch microparticles in rats
- 2007
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Ingår i: Journal of Neuroimmunology. - : Elsevier BV. - 0165-5728 .- 1872-8421. ; 183:1-2, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- Uptake of antigens and bacteria over the follicle-associated epithelium (FAE) is increased after chronic psychological stress. We investigated whether stress affects the immune response to particle-conjugated antigens taken up via the FAE. Rats were submitted to two 10-day periods of water avoidance stress and orally immunized during these periods. Stressed immunized rats displayed altered cell populations and a Th1-skewed immune response within the lymphoid follicles, together with enhanced delayed-type hypersensitivity. We conclude that chronic stress affects the cell-mediated immune response after oral immunization, which may have implications for the understanding of allergic and autoimmune diseases and development of oral vaccines.
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| 10. |
- Liu, Xiao Li, et al.
(författare)
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Characterization of the interactions of the nephrin intracellular domain
- 2005
-
Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 272:1, s. 228-243
-
Tidskriftsartikel (refereegranskat)abstract
- Nephrin is a signalling cell-cell adhesion protein of the Ig superfamily and the first identified component of the slit diaphragm that forms the critical and ultimate part of the glomerular ultrafiltration barrier. The extracellular domains of the nephrin molecules form a network of homophilic and heterophilic interactions building the structural scaffold of the slit diaphragm between the podocyte foot processes. The intracellular domain of nephrin is connected indirectly to the actin cytoskeleton, is tyrosine phosphorylated, and mediates signalling from the slit diaphragm into the podocytes. CD2AP, podocin, Fyn kinase, and phosphoinositide 3-kinase are reported intracellular interacting partners of nephrin, although the biological roles of these interactions are unclarified. To characterize the structural properties and protein-protein interactions of the nephrin intracellular domain, we produced a series of recombinant nephrin proteins. These were able to bind all previously identified ligands, although the interaction with CD2AP appeared to be of extremely low stoichiometry. Fyn phosphorylated nephrin proteins efficiently in vitro. This phosphorylation was required for the binding of phosphoinositide 3-kinase, and significantly enhanced binding of Fyn itself. A protein of 190 kDa was found to associate with the immobilized glutathione S-transferase-nephrin. Peptide mass fingerprinting and amino acid sequencing identified this protein as IQGAP1, an effector protein of small GTPases Rac1 and Cdc42 and a putative regulator of cell-cell adherens junctions. IQGAP1 is expressed in podocytes at significant levels, and could be found at the immediate vicinity of the slit diaphragm. However, further studies are needed to confirm the biological significance of this interaction and its occurrence in vivo.
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| 11. |
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| 12. |
- Ryberg, Anna, et al.
(författare)
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Concurrent genotyping of Helicobacter pylori virulence genes and human cytokine SNP sites using whole genome amplified DNA derived from minute amounts of gastric biopsy specimen DNA
- 2008
-
Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 8, s. 175-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bacterial and cellular genotyping is becoming increasingly important in the diagnosis of infectious diseases. However, difficulties in obtaining sufficient amount of bacterial and cellular DNA extracted from the same human biopsy specimens is often a limiting factor. In this study, total DNA (host and bacterial DNA) was isolated from minute amounts of gastric biopsy specimens and amplified by means of whole genome amplification using the multiple displacement amplification (MDA) technique. Subsequently, MDA-DNA was used for concurrent Helicobacter pylori and human host cellular DNA genotyping analysis using PCR-based methods. Results: Total DNA was isolated from gastric biopsy specimens of 12 subjects with gastritis and 16 control subjects having a normal mucosa. The DNA was amplified using a multiple displacement amplification (MDA) kit. Next, concurrent genotyping was performed using H. pylori-specific virulence gene PCR amplification assays, pyrosequencing of bacterial 16S rDNA and PCR characterisation of various host genes. This includes Interleukin 1-beta (IL1B) and Interferon-gamma receptor (IFNGR1) SNP analysis, and Interleukin-1 receptor antagonist (IL1RN) variable tandem repeats (VNTR) in intron 2. Finally, regions of the vacA-gene were PCR amplified using M13-sequence tagged primers which allowed for direct DNA sequencing, omitting cloning of PCR amplicons. H. pylori specific multiplex PCR assays revealed the presence of H. pylori cagA and vacA genotypic variations in 11 of 12 gastritis biopsy specimens. Using pyrosequencing, 16S rDNA variable V3 region signatures of H. pylori were found in 11 of 12 individuals with gastritis, but in none of the control subjects. Similarly, IL1B and IFNGR1-SNP and IL1RN-VNTR patterns could be established in all individuals. Furthermore, sequencing of M13-sequence tagged vacA-PCR amplicons revealed the presence of highly diverse H. pylori vacA-s/i/m regions. Conclusion: The PCR-based molecular typing methods applied, using MDA-amplified DNA derived from small amounts of gastric biopsy specimens, enabled a rapid and concurrent molecular analysis of bacterial and host genes in the same biopsy specimen. The principles and technologies used in this study could also be applied to any situation in which human host and microbial genes of interest in microbial-host interactions would need to be sequenced.
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| 13. |
- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 14. |
- Sun, Jielin, et al.
(författare)
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Sequence variants at 22q13 are associated with prostate cancer risk.
- 2009
-
Ingår i: Cancer research. - 1538-7445. ; 69:1, s. 10-5
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Tidskriftsartikel (refereegranskat)abstract
- To search for genetic variants that are associated with prostate cancer risk in the genome, we combined the data from our genome-wide association study (GWAS) in a population-based case-control study in Sweden with publicly available GWAS data from the Cancer Genetic Markers of Susceptibility (CGEMS) study. We limited the cases to those with aggressive disease in an attempt to identify risk variants that are associated with this most clinically relevant form of the disease. Among the most likely candidate single nucleotide polymorphisms (SNP) identified from the two GWAS, we sequentially confirmed one SNP at 22q13 in two independent study populations: the remaining subjects in Cancer of the Prostate in Sweden and a hospital-based case-control study at Johns Hopkins Hospital. Association of aggressive prostate cancer with the SNP at 22q13 was also observed in the publicly available data of four additional study populations from the second stage of the CGEMS study. In all seven study populations examined, the frequency of allele "C" of rs9623117 at 22q13 was consistently higher in aggressive cases than in controls. The combined allelic test was highly significant, with P = 5.0 x 10(-7). The odds ratio (OR) of allele C for aggressive prostate cancer was estimated to be 1.18 [95% confidence interval (95% CI), 1.11-1.26]. However, the SNP was also associated with nonaggressive prostate cancer, with an estimated OR of 1.11 (95% CI, 1.04-1.19; P = 0.004). The risk-associated variants are located within the genomic region of TNRC6B, a gene involved in miRNA-mediated mRNA degradation. Additional studies are warranted to further confirm the association.
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| 15. |
- Sun, Y. H., et al.
(författare)
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Theoretical studies on nonlinear optical properties of two newly synthesized compounds : EPVPC and OPVPC
- 2005
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Ingår i: Chinese Physics. - : IOP Publishing. - 1009-1963 .- 1741-4199. ; 14:1, s. 115-119
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Tidskriftsartikel (refereegranskat)abstract
- The nonlinear optical properties of two newly synthesized molecules 9-Ethyl-3-{2-[4-(2-Pyridin-4-yl-vinyl)-phenyl]vinyl}-9H-carbazole (EPVPC) and 9-Octadecyl-3-{2-[4-(2-Pyridin-4-yl-vinyl)-phenyl]-vinyl}-9H-carbazole (OPVPC) have been studied with hybrid density functional theory (DFT/B3LYP). The generalized few-state model is employed to calculate the two-photon absorption cross sections of the compounds. The theoretical results are in good agreement with the available experimental measurements. It is found that the maximal two-photon absorption (TPA) cross sections of the compounds can be well described by a three-state model. The numerical simulation shows that both compounds have large two-photon absorption (TPA) cross sections and, furthermore, OPVPC displays a little stronger TPA activity than EPVPC in a lower frequency region.
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| 16. |
- Sun, Yi, et al.
(författare)
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Heterogeneous multiscale methods for interface tracking of combustion fronts
- 2006
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Ingår i: Multiscale Modeling & simulation. - : Society for Industrial & Applied Mathematics (SIAM). - 1540-3459 .- 1540-3467. ; 5:2, s. 532-563
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we investigate the heterogeneous multiscale methods (HMM) for interface tracking and apply the technique to the simulation of combustion fronts. Our goal is to overcome the numerical difficulties, which are caused by different time scales between the transport part and the reactive part in the model equations of some interface tracking problems, such as combustion processes. HMM relies on an efficient coupling between the macroscale and microscale models. When the macroscale model is not fully known explicitly or not valid in localized regions, HMM provides a procedure for supplementing the missing data from a microscale model. Here we design and analyze a multiscale scheme in which a localized microscale model resolves the details in the model and a phase field or a front tracking method defines the interface on the macroscale. This multiscale technique overcomes the difficulty of stiffness of common problems in combustion processes. Numerical results for Majda's model and reactive Euler equations in one and two dimensions show substantially improved efficiency over traditional methods.
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| 17. |
- Sun, Yi-Qian, 1969-, et al.
(författare)
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Effects of antioxidant vitamin supplements on Helicobacter pylori-induced gastritis in Mongolian gerbils
- 2005
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 10:1, s. 33-42
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Tidskriftsartikel (refereegranskat)abstract
- Background. Epidemiological studies show that high intake of food-bound vitamin C and E reduces the risk of gastric cancer. Whether dietary supplementation with antioxidant micronutrients interferes with Helicobacter pylori infection and associated diseases is unclear. The aim of this study was to investigate if dietary vitamin C or E supplementation influences the progression of gastritis, gastric mucosal nitrosative and oxidative protein damage, gastric mucosal lipid peroxidation, or gastric mucosal oxidative DNA damage in H. pylori-infected Mongolian gerbils.Materials and methods. Gerbils were divided into four groups: H. pylori-infected animals fed with vitamin C- or vitamin E-supplemented food, and infected and uninfected animals given standard rodent food. Subgroups of animals were killed at different time-points until 52 weeks postinfection. Concentrations of 3-nitrotyrosine and thiobarbituric acid-reactive substances (TBARS) in the gastric mucosa were determined with an immunodot blot and a fluorometric method, respectively. Mucosal concentrations of carbonyl carbons on proteins and 8-hydroxydeoxyguanosine were determined by enzyme-linked immunosorbent assay. Gastritis was scored semiquantitatively.Results. Vitamin supplements had no effect on the colonization with H. pylori. Vitamin C as well as vitamin E supplements reduced mucosal 3-nitrotyrosine concentrations to normal levels in infected animals. Vitamin E supplements decreased mucosal protein carbonyls and TBARS in short-term gastritis. In addition, vitamin C supplements caused attenuated mucosal oxidative DNA damage and milder mucosal inflammation in short-term gastritis.Conclusion. Vitamin C or vitamin E supplementation leads to some short-term protective effects on H. pylori-induced gastritis in Mongolian gerbils. These effects seem to subside over time when the infection persists.
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| 18. |
- Sun, Yi-Qian, 1969-, et al.
(författare)
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Long-term morpho-functional development of Helicobacter pylori-induced gastritis in Mongolian gerbils
- 2005
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 40:10, s. 1157-1167
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE:Epidemiological studies have shown that Helicobacter pylori infection with associated chronic gastritis is the main risk factor for development of gastric cancer. The aim of this study was to investigate the long-term development of H. pylori-induced gastritis in Mongolian gerbils in terms of morphology, gastrin secretion, epithelial proliferation and gene expression of pro-inflammatory cytokines.MATERIAL AND METHODS:A total of 133 gerbils were inoculated with H. pylori and 62 served as controls. The gerbils were killed at different time-points between 6 and 94 weeks after inoculation. Serum concentrations of anti-H. pylori IgG and gastrin were determined by enzyme-linked immunoabsorbent assay (ELISA) and radioimmunoassay (RIA), respectively. Epithelial proliferation was evaluated immunohistochemically after labeling with 5-bromo-2'-deoxy-uridine. Gene expression of beta-actin, interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were measured by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Histological parameters of gastritis were assessed semiquantitatively and expressed as a "gastritis score".RESULTS:Serum concentrations of anti-H. pylori IgG and gastrin increased over time. Epithelial proliferation in the antrum was increased 6 weeks after inoculation, followed by increased proliferation in the corpus 32 weeks after inoculation. Gene expression of IL-1beta and TNF-alpha were increased in H. pylori-infected gerbils. Beta-actin was not a reliable endogenous control for RT-PCR. With time, gastritis expanded from the antrum to the corpus and the gastritis score increased to reach a peak 32 weeks after inoculation. Pseudopyloric metaplasia (loss of specialized cells) was a characteristic feature in the corpus mucosa. Gastric ulcers, but neither dysplasia nor carcinoma, were observed during 94 weeks of infection.CONCLUSIONS:Long-term H. pylori infection in Mongolian gerbils led to progressive gastritis, glandular atrophy, hypergastrinemia, increased epithelial proliferation and elevated gene expression of pro-inflammatory cytokines.
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| 19. |
- Sun, Yi-Qian, 1969-, et al.
(författare)
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Multiple strand displacement amplification of DNA isolated from human archival plasma/serum : Identification of cytokine polymorphism by pyrosequencing analysis
- 2007
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 377:1-2, s. 108-113
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Tidskriftsartikel (refereegranskat)abstract
- Background: DNA isolation from formalin-fixed paraffin-embedded tissue appears to be problematic due to degradation caused by fixative. Our aim was to investigate if the isolated genomic DNA from archival plasma/serum, combined with multiple strand displacement amplification (MDA) can be used for genotyping. Methods: Nine archival plasma/serum samples and freshly frozen gastric biopsies from the same nine H. pylori-infected subjects were used for DNA isolation. Subsequently, MDA-DNA derived from the plasma/serum samples and DNA isolated from the antrum biopsies were analyzed by PCR amplification and pyrosequencing for the presence of interleukin-1beta gene (IL-1B) single nucleotide polymorphism (SNP). In addition, Southern blot and pyrosequencing analysis of H. pylori-specific PCR amplicons were performed. Results: IL-1B SNP profiles obtained from the plasma/serum MDA-DNA and antrum biopsy DNA were identical. A C/C genotype was observed in 7 of 9 samples, and 2 of 9 revealed a C/T genotype for IL-1B - 511. Similarly, 7 of 9 had a T/T, and 2 of 9 had a C/T genotype for IL-1B - 31, 4 of 9 had a C/C, 4 of 9 had a C/T, and 1 of 9 had a T/T genotype, respectively, for IL-1B + 3954. Moreover, pyrosequencing analysis revealed the presence of H. pylori 26695 and J99-like 16S rDNA variable V3 region sequence motifs in the antrum biopsies but not in the plasma/serum samples. Conclusions: We conclude that MDA combined with pyrosequencing enables a rapid and accurate molecular typing of cytokine single nucleotide polymorphisms from archival plasma/serum samples. © 2006 Elsevier B.V. All rights reserved.
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| 20. |
- Sun, Yi-Ran, et al.
(författare)
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A Generalized Quadrature Bandpass Sampling in Radio Receivers
- 2005
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Ingår i: 10th Asia and South Pacific Design Automation Conference Shanghai, PEOPLES R CHINA, JAN 18-21, 2005. ; , s. 1288-1291
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Konferensbidrag (refereegranskat)abstract
- Bandpass sampling (BPS) realizes frequency down-conversion by undersampling. Noise aliasing as the direct consequence of the lower sampling rate causes a performance degradation. In this paper, a generalized quadrature BPS (GQBPS) combined with a filter which performs both reconstruction and bandpass filtering is studied in the frequency domain with respect to both signal reconstruction and noise aliasing reduction. The theoretical analyses show that GQBPS might be a potential way to reduce noise aliasing at the cost of a more complicated reconstruction algorithm.
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| 21. |
- Sun, Yi-Ran, et al.
(författare)
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Analysis and Implementation of Uniform Quadrature Bandpass Sampling
- 2005
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Ingår i: 2005 IEEE WORKSHOP ON SIGNAL PROCESSING SYSTEMS. - 0780393333 ; , s. 137-142
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Konferensbidrag (refereegranskat)abstract
- Sampling noise folding causes a large SNR degradation at the output of BandPass Sampling (BPS) system. A sampling architecture based on Generalized Quadrature BandPass Sampling (GQBPS) was proposed in [1]. Theoretical analysis showed that such architecture is promising to reduce the SNR degradation due to noise aliasing. In this paper, Uniform Quadrature BandPass Sampling (UQBPS) as a special case of GQBPS is analyzed for both ideal sampling and a sample-and-hold. One available implementation method to UQBPS is shown and discussed at the circuit level.
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| 22. |
- Sun, Yi Ran, et al.
(författare)
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Effects of Noise and Jitter in Bandpass Sampling
- 2005
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Ingår i: ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING. ; , s. 85-97
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Konferensbidrag (refereegranskat)abstract
- BandPass Sampling (BPS) is an undersampling technique by intentional aliasing. BPS enables one to have an interface between the IF stage and the ADC in a radio receiver. Conventional uniform BPS at Nyquist rate normally results in a low Signal-to-Noise Ratio (SNR) due to noise spectrum aliasing. The noise (e.g. kT/C noise introduced in a voltage-mode sampler) is combined in each of the Nyquist bands within the bandwidth of the sampling device. Also timing jitter causes a performance degradation in BPS. In this paper, signal spectrum aliasing, noise aliasing and jitter effects in BPS is analyzed. It is verified by simulation that NonUniform Sampling (NUS) has the potential to suppress signal spectrum aliasing and relax the requirement on the anti-aliasing (AA) filter. Jitter effects in BPS are compared to LowPass Sampling (LPS) case. However, a signal cannot be reconstructed from its nonuniform samples by using only ideal lowpass filtering (classic Shannon's reconstruction). Finally, signal reconstruction in the presence of noise and jitter are investigated for three Reconstruction Algorithms (RAs) aimed at NUS.
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| 23. |
- Sun, Yi-Ran, et al.
(författare)
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Filtering Transformation in GeneralizedQuadrature Bandpass Sampling
- 2005
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Ingår i: Electronics, Circuits and Systems, 2005. ICECS 2005. 12th IEEE International Conference on Electronics, Circuits and Systems (ICECS), Tunis, Tunisia, December2005.. ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- According to recent research, Generalized Quadrature BandPass Sampling (GQBPS) with FIR filtering is promising to deal with the noise aliasing problem in subsampling systems. However, the interesting band of folded spectra by GQBPS with real FIR filtering is still located at the input carrier frequency. In this paper, inherent FIR filtering in GQBPS with real coefficients is transformed such that the interesting band is shifted to a lower frequency. The main advantage of such transformation is to achieve a frequency downconversion besides sampling and dealing with noise aliasing in GQBPS. As a special case of GQBPS, Uniform Quadrature BandPass Sampling (UQBPS) is also discussed including the filter transformation. Both theoretical analyses and simulations are included. It is verified that the expected noise aliasing improvement of GQBPS or UQBPS does not change with the filter transformation. The whole subsampling system with GQBPS or UQBPS might be simplified by using complex filtering.
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| 24. |
- Sun, Yi-Ran, 1976-
(författare)
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Generalized Bandpass Sampling Receivers for Software Defined Radio
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Based on different sampling theorem, for example classic Shannon’s sampling theorem and Papoulis’ generalized sampling theorem, signals are processed by the sampling devices without loss of information. As an interface between radio receiver front-ends and digital signal processing blocks, sampling devices play a dominant role in digital radio communications. Under the concept of Software Defined Radio (SDR), radio systems are going through the second evolution that mixes analog, digital and software technologies in modern radio designs. One design goal of SDR is to put the A/D converter as close as possible to the antenna. BandPass Sampling (BPS) enables one to have an interface between the RF or the higher IF signal and the A/D converter, and it might be a solution to SDR. However, three sources of performance degradation present in BPS systems, harmful signal spectral overlapping, noise aliasing and sampling timing jitter, hinder the conventional BPS theory from practical circuit implementations. In this thesis work, Generalized Quadrature BandPass Sampling (GQBPS) is first invented and comprehensively studied with focus on the noise aliasing problem. GQBPS consists of both BPS and FIR filtering that can use either real or complex coefficients. By well-designed FIR filtering, GQBPS can also perform frequency down-conversion in addition to noise aliasing reduction. GQBPS is a nonuniform sampling method in most cases. With respect to real circuit implementations, uniform sampling is easier to be realized compared to nonuniform sampling. GQBPS has been also extended to Generalized Uniform BandPass Sampling (GUBPS). GUBPS shares the same property of noise aliasing suppression as GQBPS besides that the samples are uniformly spaced. Due to the moving average operation of FIR filtering, the effect of sampling jitter is also reduced to a certain degree in GQBPS and GUBPS. By choosing a suitable sampling rate, harmful signal spectral overlapping can be avoided. Due to the property of quadrature sampling, the “self image” problem caused by I/Q mismatches is eliminated. Comprehensive theoretical analyses and program simulations on GQBPS and GUBPS have been done based on a general mathematic model. Circuit architecture to implementing GUBPS in Switched-Capacitor circuit technique has been proposed and analyzed. To improve the selectivity at the sampling output, FIR filtering is extended by adding a 1st order complex IIR filter in the implementation. GQBPS and GUBPS operate in voltage-mode. Besides voltage sampling, BPS can also be realized by charge sampling in current-mode. Most other research groups in this area are focusing on bandpass charge sampling. However, the theoretical analysis shows that our GQBPS and GUBPS in voltage mode are more efficient to suppress noise aliasing as compared to bandpass charge sampling with embedded filtering. The aliasing bands of sampled-data spectrum are always weighted by continuous-frequency factors for bandpass charge sampling with embedded filtering while discrete-frequency factors for GQBPS and GUBPS. The transmission zeros of intrinsic filtering will eliminate the corresponding whole aliasing bands of both signal and noise in GQBPS and GUBPS, while it will only cause notches at a limited set of frequencies in bandpass charge sampling. In addition, charge sampling performs an intrinsic continuous-time sinc function that always includes lowpass filtering. This is a drawback for a bandpass input signal.
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| 25. |
- Sun, Yi-Ran, et al.
(författare)
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Generalized bandpass sampling with complex FIR filtering
- 2006
-
Ingår i: 2006 IEEE Asia Pacific Conference on Circuits and Systems. - NEW YORK : IEEE. - 9781424403868 ; , s. 1035-1038
-
Konferensbidrag (refereegranskat)abstract
- In this paper, Generalized Quadrature BandPass Sampling (GQBPS) with complex FIR filtering is studied with respect to both noise and jitter. GQBPS is a type of nonuniform sampling, and has been extended to Generalized Uniform BandPass Sampling (GUBPS). It is shown that GQBPS and GUBPS with complex FIR filtering perform both down-conversion and noise aliasing suppression in addition to sampling. Due to the averaging operation of FIR filtering, sampling jitter is also reduced to a certain degree by GQBPS and GUBPS. However, the performance by GQBPS is limited by the maximum effective sampling rate determined by the fixed time resolution of the sampling scheme. In contrast GUBPS avoids this problem.
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| 26. |
- Sun, Yi-Ran, et al.
(författare)
-
Generalized Quadrature Bandpass Sampling with FIR Filtering
- 2005
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Ingår i: 2005 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS), VOLS 1-6, CONFERENCE PROCEEDINGS. ; , s. 4429-4432
-
Konferensbidrag (refereegranskat)abstract
- In this paper, generalized quadrature BandPass Sampling (BPS) in voltage-mode with inherent FIR filtering is presented. By using the theory of sampling equivalence, this sampling strategy is comparable to another strategy, charge sampling with intrinsic IIR filtering. The theoretical analysis and simulation results show that this inherent FIR filtering not only has the advantage to reject or attenuate images and interferences, but is also helpful to suppress noise aliasing. A realizable implementation of the proposed sampling strategy by uniform quadrature BPS (UQBPS) promises to suppress noise aliasing in BPS systems to a large extent.
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| 27. |
- Sun, Yi-Ran, et al.
(författare)
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Implementation of generalized uniform bandpass sampling with complex FIR and IIR filtering
- 2007
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Ingår i: 2007 European Conference On Circuit Theory And Design. ; , s. 476-479
-
Konferensbidrag (refereegranskat)abstract
- BandPass Sampling (BPS) realizes frequency down-conversion in radio receiver front-ends by a sampling rate that can be slightly larger than twice the information bandwidth compared to twice the highest frequency for traditional LowPass Sampling (LPS). However, some implementation problems, harmful signal spectral folding, noise aliasing and sampling jitter, are unavoidably present in conventional BPS systems. Under recent research, generalized bandpass sampling combined with filtering has been proposed for dealing with these problems. In this paper, the novel sampling architectures with intrinsic filtering are implemented using a sampled-data technique called Switched-Capacitor (SC) circuit technique. Specifically complex SC filtering is designed and analyzed. Both the analysis and simulation results show that the designed complex SC filter fulfils the expectations of generalized bandpass sampling.
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| 28. |
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| 29. |
- Wang, Chuan-Kui, et al.
(författare)
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Breakdown of optical power limiting and dynamical two-photon absorption for femtosecond laser pulses in molecular medium
- 2007
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Ingår i: Journal of the Optical Society of America. B, Optical physics. - 0740-3224 .- 1520-8540. ; 24:9, s. 2436-2442
-
Tidskriftsartikel (refereegranskat)abstract
- We solve numerically the Maxwell-Bloch equations using an iterative predictor-corrector finite-difference time-domain technique to study the propagation of femtosecond laser pulses in a strong two-photon absorption (TPA) organic molecular medium [4,4'-bis(dimethylamino) stilbene]. The hybrid density functional theory is used to calculate electronic structures of the compound. The molecular system is described by a three-level model in an optical regime and has demonstrated a good optical power limiting behavior in a certain intensity region. Thresholds for the breakdown of optical power limiting are observed that are dependent on the input pulse width and, slightly, the propagation distance. The dynamical two-photon absorption cross section is obtained, which is almost a linearly increasing function of the pulse width in the femtosecond time domain. The propagation distance also has an obvious influence on the measurement of the TPA cross section, and non-monotonic dependence of the TPA cross section on propagation distance is observed. The input pulse width and the thickness of the molecular samples thus should be taken into account when the TPA cross section is measured.
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| 30. |
- Wang, Mo-Jin, et al.
(författare)
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The Ile646Val (2073A > G) Polymorphism in the Kinase-Binding Domain of A-Kinase Anchoring Protein 10 and the Risk of Colorectal Cancer
- 2009
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Ingår i: ONCOLOGY. - : S. Karger AG. - 0030-2414 .- 1423-0232. ; 76:3, s. 199-204
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The purpose of this study is to investigate whether the Ile646Val (2073A>G) polymorphism in the kinase-binding domain of A-kinase anchoring protein 10 (AKAP10) is related to the risk of colorectal cancer (CRC), clinicopathological variables and the environmental factors for the development of CRC. Methods: Applying TaqMan allelic discrimination, we investigated AKAP10 Ile646Val (2073A>G) polymorphism in 288 Chinese CRC patients and 281 healthy controls. Results: Logistic regression analysis revealed a significant association of AKAP10 Ile646Val (2073A>G) polymorphism with increased CRC risk (adjusted OR = 1.44, 95% CI 1.01-2.07, p = 0.02). Stratification analysis showed that the increased risk associated with the variant genotypes (GG+AG) was more evident in male subjects (adjusted OR = 1.48, 95% CI 0.94-2.34, p = 0.03). Compared with the AA genotype, the adjusted OR for the variant genotypes was 1.81 (95% CI 1.08 - 3.05, p = 0.01) among young subjects (age ! 57 years). Among individuals who did not smoke or who smoked lightly, there was a significantly increased risk with the variant genotypes (adjusted OR = 1.66, 95% CI 1.08 - 2.56, p = 0.02). We did not observe a relationship between the AKAP10 polymorphism and other clinicopathological and environmental factors. Conclusions: Our data suggested that the AKAP10 2073A>G variation is associated with an increased risk of CRC in the Chinese population.
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| 31. |
- Yu, G., et al.
(författare)
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Structures, electronic states, photoluminescence, and carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles
- 2005
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 127:17, s. 6335-6346
-
Forskningsöversikt (refereegranskat)abstract
- The excellent electroluminescent (EL) properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles, 1-methyl-1,2,3,4,5-pentaphenylsilole (MPPS), and 1,1,2,3,4,5-hexaphenylsilole (HPS) have been found. Despite some studies devoted to these materials, very little is known about the real origin of their unique EL properties. Therefore, we investigated the structures, photoluminescence (PL), and charge carrier transport properties of 1,1-disubstituted 2,3,4,5-tetraphenylsiloles as well as the effect of substituents on these characteristics. The single crystals of the three siloles involving 1,1-dimethyl-2,3,4,5-tetraphenylsilole (DMTPS), MPPS, and HIPS were grown and their crystal structures were determined by X-ray diffraction. Three siloles have nonplanar molecular structures. The substituents at 1,1-positions enhance the steric hindrance and have predominant influence on the twisted degree of phenyl groups at ring carbons. This nonplanar structure reduces the intermolecular interaction and the likelihood of excimer formation, and increases PL efficiency in the solid state. The silole films show high fluorescence quantum yields (75-85%), whereas their dilute solutions exhibit a faint emission. The electronic structures of the three siloles were investigated using quantum chemical calculations. The highest occupied molecular orbitals (HOMOs) and the lowest unoccupied molecular orbitals (LUMOs) are mainly localized on the silole ring and two phenyl groups at 2,5-positions in all cases, while the LUMOs have a significant orbital density at two exocyclic Si-C bonds. The extremely theoretical studies of luminescent properties were carried out. We calculated the nonradiative decay rate of the first excited state as well as the radiative one. It is found that the faint emission of DMTPS in solutions mainly results from the huge nonradiative decay rate. In solid states, molecular packing can remarkably restrict the intramolecular rotation of the peripheral side phenyl ring, which has a large contribution to the nonradiative transition process. This explains why the 1,1-disubstituted 2,3,4,5-tetraphenylsiloles in the thin films exhibit high fluorescence quantum yields. The charge carrier mobilities of the MPPS and HPS films were measured using a transient EL technique. We obtained a mobility of 2.1 x 10(-6) cm(2)/V(.)s in the MPPS film at an electric field of 1.2 x 10(6) V/cm. This mobility is comparable to that of Alq(3), which is one of the most extensively used electron transport materials in organic light-emitting diodes (LEDs), at the same electric field. The electron mobility of the HPS film is about similar to 1.5 times higher than that of the MPPS film. To the best of our knowledge, this kind of material is one of the most excellent emissive materials that possess both high charge carrier mobility and high PL efficiency in the solid states simultaneously. The excellent EL performances of MPPS and HPS are presumably ascribed to these characteristics.
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| 32. |
- Yu, Ling-Zhu, et al.
(författare)
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MEK1/2 regulates microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte meiotic maturation.
- 2007
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Ingår i: Cell cycle (Georgetown, Tex.). - 1551-4005. ; 6:3, s. 330-8
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Tidskriftsartikel (refereegranskat)abstract
- It is well known that MAPK plays pivotal roles in oocyte maturation, but the function of MEK (MAPK kinase) remains unknown. We have studied the expression, subcellular localization and functional roles of MEK during meiotic maturation of mouse oocytes. Firstly, we found that MEK1/2 phoshorylation (p-MEK1/2, indicative of MEK activation) was low in GV (germinal vesicle) stage, increased 2h after GVBD (germinal vesicle breakdown), and reached the maximum at metaphase II. Secondly, we found that P-MEK1/2 was restricted in the GV prior to GVBD. In prometaphase I and metaphase I, P-MEK1/2 was mainly associated with the spindle, especially with the spindle poles. At anaphase I and telophase I, p-MEK1/2 became diffusely distributed in the region between the separating chromosomes, and then became associated with the midbody. The association of p-MEK1/2 with spindle poles was further confirmed by its colocalization with the centrosomal proteins, gamma-tubulin and NuMA. Thirdly, we have investigated the possible functional role of MEK1/2 activation by intravenous administration and intrabursal injection of a specific MEK inhibitor, U0126, and by microinjection of MEK siRNA into oocytes. All these manipulations cause disorganized spindle poles and spindle structure, misaligned chromosomes and larger than normal polar bodies. Our results suggest that MEK1/2 may function as a centrosomal protein and may have roles in microtubule organization, spindle pole tethering and asymmetric division during mouse oocyte maturation.
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| 33. |
- Zhang, Ting-Ting, et al.
(författare)
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Protophilicity, electrochemical property, and desulfurization of diiron dithiolate complexes containing a functionalized C-2 bridge with two vicinal basic sites
- 2009
-
Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387 .- 1873-3719. ; 28:6, s. 1138-1144
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Tidskriftsartikel (refereegranskat)abstract
- Two chiron dithiolate complexes [{mu-SC(NBn)CH(NHBn)S-mu)Fe-2(CO)(5)L] (L = PPh3, 2; P(Pyr)(3), 3) containing a functionlized C-2 bridge with two vicinal basic sites were prepared and characterized as models of the FeFe-hydrogenase active site. The molecular structures of 2 and its N-protonated form [(2H(N))(OTf)] were determined by X-ray analyses of single crystals. In the solid state of [(2HN)(OTf)]. Each asymmetric unit contains a molecule of [(2H(N))(OTf)] and a molecule of water. The molecule of water is close to the iron atom of the [Fe(CO)(3)] unit (Fe center dot center dot center dot O(H2O), 4J 99 angstrom). The complexes 2 and 3 are relatively protophilic. P-31 NMR spectra and cyclic voltammograms show that they can be protonated by the mild acids CCl3COOH and CF3COOH. Electrochemical studies show that the first reduction peak of 3 at - 1.51 V versus Fc(+)/Fc is 110 mV more positive than that (-1.62V) found for the analogous diiron azadithiolate complex [{(mu-SCH2)N(CH2C6H5)}Fe-2(CO)(5)P(Pyr)(3)] (7). Protonation of 2 and 3 leads to the anodic shifts of 610-650 mV for the (FeFe1)-Fe-1/(FeFe0)-Fe-1 reduction potentials. The shifts are apparently larger than that (450 mV) for protonation of 7. The reaction of the all-carbonyl complex [{(mu-SC(NBn)CH(NHBn)S-mu}Fe-2(CO)(5)L] with two equivalents of bis(diphenylphosphino)methane (dppm) in refluxing toluene affords a desulfurized complex 1(mu-S)(mu-dppm)(2)Fe-2(CO)(4)] (6). The reaction process was studied. A dppm mono-dentate intermediate [{mu-SC(NBn)CH(NHBn)S-mu)Fe-2(CO)(5)(kappa(1)-dppm)] (4) and a dppm mu-bridging species [{mu-SC(NBn)CH(NHBn)S-mu)Fe-2(CO)(4)(mu-dppm)] (5) have been isolated and spectroscopically characterized.
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| 34. |
- Zhang, Wei-Wei, et al.
(författare)
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Thermodynamic Assessment of the Cu-B System Supported by Key Experiment and First-Principles Calculations
- 2009
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Ingår i: Journal of Phase Equilibria and Diffusion. - : Springer Science and Business Media LLC. - 1547-7037 .- 1863-7345. ; 30:5, s. 480-486
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Tidskriftsartikel (refereegranskat)abstract
- The Cu-B system was investigated via a hybrid approach of key experiment and thermodynamic modeling. Based on the critically assessed Cu-B phase diagram, seven crucial alloys were selected and prepared by arc melting the pure elements. An inductively coupled plasma-atomic emission spectrometric analysis was conducted to determine the compositions of the prepared alloys. The phase equilibria were determined by using x-ray diffraction, electron probe microanalysis, and differential thermal analysis. The temperature associated with the eutectic reaction, L double left right arrow (B) + (Cu); was measured to be 1028 +/- 2 degrees C. First-principles calculations indicate that the energy of inserting a B atom into the interstitial vacancy (Va) site of the lattice for Cu atoms is marginally lower than that of substituting for a Cu atom with a B atom. Consequently, the sublattice model (Cu)(B, Va) in which B atoms occupy the interstitial sites was employed for the fcc (Cu) phase rather than the model (Cu, B)(Va) in which B atoms substitute for Cu atoms. A thermodynamic modeling of the Cu-B system was then performed by considering the reliable literature data and the present experimental results. A good agreement between modeling and experiment was obtained.
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| 35. |
- Zhao, K., et al.
(författare)
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Studies on two-photon absorption cross-sections of 1,4-dimethoxy-2,5-divinyl-benzene derivatives
- 2005
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 54:6, s. 2662-2668
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Tidskriftsartikel (refereegranskat)abstract
- The one-photon and two-photon absorption properties of a series of 1, 4-dimethoxy-2, 5-divinyl-benzene derivatives are investigated by use of the analytic response theory at HF level. The one-photon and two-photon fluorescence spectra of E, E-2-5Bis[4'-(N, N-di-n-butylamino) styryl]-1 4-dimenthoxybenzene are measured. The numerical results show that these molecules have strong two-photon absorption cross sections. In the visible light region, the maximal one-photon absorption strengths of the molecules occur in the first excited state. Furthermore, the maximal two-photon absorption cross sections of the D-pi-A typed molecules still appear in the first state, but for D-pi-D typed molecules the second excited state has the maximal two-photon absorption cross-section. The optical properties of the molecules are closely related to the electric property of the donor and acceptor. The symmetrically substituted molecules can not be determined to have a larger two-photon absorption cross section than the asymmetrically substituted molecules for such a kind of pi-center. The charge-transfer process for the charge-transfer states is displayed, and then the mechanism of photopolymerization is discussed qualitatively.
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| 36. |
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| 37. |
- Zheng, S. Lilly, et al.
(författare)
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Genetic variants and family history predict prostate cancer similar to prostate-specific antigen
- 2009
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 15:3, s. 1105-1111
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Although prostate-specific antigen (PSA) is the best biomarker for predicting prostate cancer, its predictive performance needs to be improved. Results from the Prostate Cancer Prevention Trial revealed the overall performance measured by the areas under curve of the receiver operating characteristic at 0.68. The goal of the present study is to assess the ability of genetic variants as a PSA-independent method to predict prostate cancer risk. EXPERIMENTAL DESIGN: We systematically evaluated all prostate cancer risk variants that were identified from genome-wide association studies during the past year in a large population-based prostate cancer case-control study population in Sweden, including 2,893 prostate cancer patients and 1,781 men without prostate cancer. RESULTS: Twelve single nucleotide polymorphisms were independently associated with prostate cancer risk in this Swedish study population. Using a cutoff of any 11 risk alleles or family history, the sensitivity and specificity for predicting prostate cancer were 0.25 and 0.86, respectively. The overall predictive performance of prostate cancer using genetic variants, family history, and age, measured by areas under curve was 0.65 (95% confidence interval, 0.63-0.66), significantly improved over that of family history and age (0.61%; 95% confidence interval, 0.59-0.62; P = 2.3 x 10(-10)). CONCLUSION: The predictive performance for prostate cancer using genetic variants and family history is similar to that of PSA. The utility of genetic testing, alone and in combination with PSA levels, should be evaluated in large studies such as the European Randomized Study for Prostate Cancer trial and Prostate Cancer Prevention Trial.
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| 38. |
- Zheng, S. Lilly, et al.
(författare)
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Two independent prostate cancer risk-associated Loci at 11q13
- 2009
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Ingår i: Cancer Epidemiology, Biomarkers and Prevention. - 1055-9965 .- 1538-7755. ; 18:6, s. 1815-1820
-
Tidskriftsartikel (refereegranskat)abstract
- Single nucleotide polymorphisms (SNP) at 11q13 were recently implicated in prostate cancer risk by two genome-wide association studies and were consistently replicated in multiple study populations. To explore prostate cancer association in the regions flanking these SNPs, we genotyped 31 tagging SNPs in a approximately 110 kb region at 11q13 in a Swedish case-control study (Cancer of the Prostate in Sweden), including 2,899 cases and 1,722 controls. We found evidence of prostate cancer association for the previously implicated SNPs including rs10896449, which we termed locus 1. In addition, multiple SNPs on the centromeric side of the region, including rs12418451, were also significantly associated with prostate cancer risk (termed locus 2). The two groups of SNPs were separated by a recombination hotspot. We then evaluated these two representative SNPs in an additional approximately 4,000 cases and approximately 3,000 controls from three study populations and confirmed both loci at 11q13. In the combined allelic test of all four populations, P = 4.0 x 10(-11) for rs10896449 at locus 1 and P = 1.2 x 10(-6) for rs12418451 at locus 2, and both remained significant after adjusting for the other locus and study population. The prostate cancer association at these two 11q13 loci was unlikely confounded by prostate-specific antigen (PSA) detection bias because neither SNP was associated with PSA levels in controls. Unlike locus 1, in which no known gene is located, several putative mRNAs are in close proximity to locus 2. Additional confirmation studies at locus 2 and functional studies for both loci are needed to advance our knowledge on the etiology of prostate cancer.
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| 39. |
- Zhong, H. M., et al.
(författare)
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A first principles study on optical transparency mechanism in Dy doped alpha-SiAlON ceramics
- 2009
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 106:9
-
Tidskriftsartikel (refereegranskat)abstract
- Dy doped alpha-SiAlON ceramics prepared by the hot-pressing method show a high optical transmittance value, >70%, in the infrared region of 1.5-4.5 mu m. First principles calculations have been carried out to reveal the underlying transparency mechanism. It is found that the valence shell of doped Dy atoms interacts strongly with the doping states of alpha-SiAlON, resulting in the increase in the optical gap from 0.4 to 1.1 eV, which suppresses the photoabsorption in the wavelength region longer than 1.0 mu m and leads to the good transparency property. The calculated optical transmission spectra are in good agreement with the corresponding experiments.
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| 40. |
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