| 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. |
- Aaron, F. D., et al.
(författare)
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Multi-leptons with high transverse momentum at HERA
- 2009
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Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479. ; :10
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Tidskriftsartikel (refereegranskat)abstract
- Events with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb(-1). The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e(+)p collision data with a scalar sum of the lepton transverse momenta above 100 GeV while 1.94 +/- 0.17 events are expected. Such events are not observed in e(-)p collisions for which 1.19 +/- 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions.
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| 3. |
- Fang, Fang, et al.
(författare)
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Molecular phylogenetic interrelationships of the south Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae)
- 2009
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Ingår i: Zoologica Scripta. - : Wiley. - 0300-3256 .- 1463-6409. ; 38:3, s. 237-256
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Tidskriftsartikel (refereegranskat)abstract
- Molecular analysis of mitochondrial cytochrome b sequences from 159 species of the family Cyprinidae supports the subfamily Danioninae, of which Rasborinae is shown to be a junior synonym. Analysis of combined cytochrome b and a fragment of the nuclear rhodopsin gene from 68 species, including 43 species representing the subfamily Danioninae, supports phylogenetic distinctness of Danio and Devario. In the combined molecular analysis Microrasbora rubescens, Chela, Laubuca, Devario, and Inlecypris form a clade with M. gatesi, M. nana and M. kubotai being in sister group position to the rest. The sister group of this Devario clade is Danio. Inlecypris is synonymized with Devario. Microdevario, new genus, is proposed for M. gatesi, M. nana and M. kubotai, supported by morphological characters. In the cytochrome b analysis, M. rubescens falls outside Devario, and there is no morphological support for including M. rubescens in Devario. In the cytochrome b analysis Esomus+Danionella is the sister group of Danio and Devario clades, whereas in individual rhodopsin and combined analyses Esomus is the sister group of Danio, and of Danio and the Devario clade, respectively. Sundadanio presents at least one strong morphological synapomorphy with Danio, but is positioned in molecular trees either as a member of the Cyprininae or as sister group of the remaining Danioninae. In the morphological analysis, small-sized species grouped together based on shared reductions that are not necessarily synapomorphies. In the molecular analysis, small-sized species such as Danionella and Sundadanio possess long branches and their position varies, but they did not group together. This suggests morphological homoplasy, but phylogenetic positions are not well supported in the molecular analyses.
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| 4. |
- Cao, Xianhua, et al.
(författare)
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Why is it challenging to predict intestinal drug absorption and oral bioavailability in human using rat model
- 2006
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Ingår i: Pharmaceutical research. - : Springer Science and Business Media LLC. - 0724-8741 .- 1573-904X. ; 23:8, s. 1675-1686
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Tidskriftsartikel (refereegranskat)abstract
- Purpose. To study the correlation of intestinal absorption for drugs with various absorption routes between human and rat, and to explore the underlying molecular mechanisms for the similarity in drug intestinal absorption and the differences in oral bioavailability between human and rat. Materials and Methods. The intestinal permeabilities of 14 drugs and three drug-like compounds with different absorption mechanisms in rat and human jejunum were determined by in situ intestinal perfusion. A total of 48 drugs were selected for oral bioavailability comparison. Expression profiles of transporters and metabolizing enzymes in both rat and human intestines (duodenum and colon) were measured using GeneChip analysis. Results. No correlation (r(2) = 0.29) was found in oral drug bioavailability between rat and human, while a correlation (r(2) = 0.8) was observed for drug intestinal permeability with both carrier-mediated absorption and passive diffusion mechanisms between human and rat small intestine. Moderate correlation (with r(2) > 0.56) was also found for the expression levels of transporters in the duodenum of human and rat, which provides the molecular mechanisms for the similarity and correlation of drug absorption between two species. In contrast, no correlation was found for the expressions of metabolizing enzymes between rat and human intestine, which indicates the difference in drug metabolism and oral bioavailability in two species. Detailed analysis indicates that many transporters (such as PepT1, SGLT-1, GLUT5, MRP2, NT2, and high affinity glutamate transporter) share similar expression levels in both human and rat with regional dependent expression patterns, which have high expression in the small intestine and low expression in the colon. However, discrepancy was also observed for several other transporters (such as MDR1, MRP3, GLUT1, and GLUT3) in both the duodenum and colon of human and rat. In addition, the expressions of metabolizing enzymes (CYP3A4/CYP3A9 and UDPG) showed 12 to 193-fold difference between human and rat intestine with distinct regional dependent expression patterns. Conclusions. The data indicate that rat and human show similar drug intestinal absorption profiles and similar transporter expression patterns in the small intestine, while the two species exhibit distinct expression levels and patterns for metabolizing enzymes in the intestine. Therefore, a rat model can be used to predict oral drug absorption in the small intestine of human, but not to predict drug metabolism or oral bioavailability in human.
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| 5. |
- Fang, Hsin-Yu, et al.
(författare)
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Hypoxia-inducible factors 1 and 2 are important transcriptional effectors in primary macrophages experiencing hypoxia
- 2009
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 114:4, s. 844-859
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Tidskriftsartikel (refereegranskat)abstract
- Ischemia exists in many diseased tissues, including arthritic joints, atherosclerotic plaques, and malignant tumors. Macrophages accumulate in these sites and up-regulate hypoxia-inducible transcription factors (HIFs) 1 and 2 in response to the hypoxia present. Here we show that the gene expression profile in primary human and murine macrophages changes markedly when they are exposed to hypoxia for 18 hours. For example, they were seen to up-regulate the cell surface receptors, CXCR4 and GLUT1, and the potent, tumor-promoting cytokines, vascular endothelial growth factor A, interleukin (IL)-1 beta and IL-8, adrenomedullin, CXCR4, and angiopoietin-2. Hypoxia also stimulated their expression and/or phosphorylation of various proteins in the nuclear factor-kappa B (NF-kappa B) signaling pathway. We then used both genetic and pharmacologic methods to manipulate the levels of HIFs-1 alpha and 2 alpha or NF-kappa B in primary macrophages to elucidate their role in the hypoxic induction of many of these key genes. These studies showed that both HIF-1 and -2, but not NF-kappa B, are important transcriptional effectors regulating the responses of macrophages to such a period of hypoxia. Further studies using experimental mouse models are now warranted to investigate the role of such macrophage responses in the progression of various diseased tissues, such as malignant tumors. (Blood. 2009; 114: 844-859)
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| 6. |
- Gao, Feng, et al.
(författare)
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Visible-light photocatalytic properties of weak magnetic BiFeO3 nanoparticles
- 2007
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Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 19:19, s. 2889-2892
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline BiFeO3 nanoparticles (size 80-120 nm) are prepared by a simple sol-gel technique. Such nanoparticles are very efficient for photocatalytic decomposition of organic contaminants under irradiation from ultraviolet to visible frequencies. The BiFeO3 nanoparticles also demonstrate weak ferromagnetism of about 0.06 mu(B)/Fe at room temperature, in good agreement with theoretical calculations.
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| 7. |
- He, Lu-Jun, et al.
(författare)
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Genetic polymorphisms of N-acetyltransferase 2 and colorectal cancer risk.
- 2005
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Ingår i: World Journal of Gastroenterology. - 1007-9327 .- 2219-2840. ; 11:27, s. 4268-4271
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To identify the distribution of N-acetyltrasferase 2(NAT2) polymorphism in Hebei Han Chinese and the effects of the polymorphism on the development of colorectal cancer. METHODS: We performed a hospital-based case-control study of 237 healthy individuals and 83 colorectal cancer patients of Hebei Han Chinese. DNA was extracted from peripheral blood and cancer tissues. The genotypes of the polymorphisms were assessed by PCR-restriction fragment length polymorphism (RFLP). RESULTS: There were four NAT2 alleles of WT, M1, M2, and M3 both in the healthy subjects and in the patients, and 10 genotypes of WT/WT, WT/M1, WT/M2, WT/M3, M1/M1, M1/M2, M1/M3, M2/M2, M2/M3, M3/M3. M2 allele was present in 15.61% of healthy subjects and 29.52% of patients (chi(2) = 15.31, P<0.0001), and M3 allele was present in 30.59% of healthy subjects and 16.87% of patients (chi(2) = 25.33, P<0.0001). There were more WT/M2 (chi(2) = 34.42, P<0.0001, odd ratio = 4.99, 95%CI = 2.27-9.38) and less WT/M3 (chi(2) = 3.80, P = 0.03) in the patients than in the healthy subjects. In 70.3% of the patients, there was a difference in NAT2 genotype between their tumors and blood cells. Patients had more WT/M2 (chi(2) = 5.11, P = 0.02) and less M2/M3 (chi(2) = 4.27, P = 0.039) in their blood cells than in the tumors. Furthermore, 53.8% (7/13) of M2/M3 in tumors were from WT/M2 of blood cells. CONCLUSION: There is a possible relationship between the NAT2 polymorphisms and colorectal cancer in Hebei Han Chinese. The genotype WT/M2 may be a risk factor for colorectal cancer.
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| 8. |
- Wang, Shanshan, et al.
(författare)
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Endface reflectivities of optical nanowires
- 2009
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Ingår i: Optics Express. - 1094-4087. ; 17:13, s. 10881-10886
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Tidskriftsartikel (refereegranskat)abstract
- Endface reflectivities (ERs) of optical nanowires are investigated using three-dimensional finite-difference time-domain simulations. Typical ERs of both free-standing and substrate-supported silica, tellurite, PMMA and semiconductor nanowires or nanofibers are obtained. Unlike in conventional waveguides such as optical fibers, ERs of nanowires are usually considerably lower when operated in single mode. Dependences of ER on the diameter and the refractive index of the nanowire, and the wavelength of the guided light are also investigated. These results are helpful for estimating and understanding ERs in optical nanowires with diameters close to or smaller than the wavelengths of the light, and may offer valuable references for practical applications such as nanowire or nanofiber-based resonators and lasers.
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| 9. |
- 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
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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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| 10. |
- Yu, ZZ, et al.
(författare)
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Adiponectin is related to carotid artery plaque and a predictor of cardiovascular outcome in a cohort of non-diabetic peritoneal dialysis patients
- 2008
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Ingår i: Blood purification. - : S. Karger AG. - 1421-9735 .- 0253-5068. ; 26:4, s. 386-393
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Tidskriftsartikel (refereegranskat)abstract
- <i>Aims:</i> Adiponectin is an adipocytokine with antiatherogenic and anti-inflammatory properties. We investigated associations between circulating adiponectin, inflammation and cardiovascular disease in peritoneal dialysis patients. <i>Methods:</i> A prospective study was performed in 59 non-diabetic patients. The concentrations of serum adiponectin, biochemical data and ultrasound of carotid artery were measured at enrollment. The patients were followed up to 39 months mainly for cardiovascular events. <i>Results:</i> The serum adiponectin concentration was elevated and inversely related to C-reactive protein and interleukin-6 in the patients. The adiponectin level of patients with carotid plaques was significantly lower than in those without plaques (p < 0.01). Kaplan-Meier analysis showed that the cumulative survival without new cardiovascular events was better in patients with higher adiponectin levels than in those with lower adiponectin levels. <i>Conclusion:</i> Serum adiponectin levels are inversely related with markers of systemic inflammation and signs of atherosclerosis which may explain why hyperadiponectinemia in this study was associated with better cardiovascular outcome.
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