| 1. |
- Adcox, K, et al.
(författare)
-
PHENIX detector overview
- 2003
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 499:2-3, s. 469-479
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Tidskriftsartikel (refereegranskat)abstract
- The PHENIX detector is designed to perform a broad study of A-A, p-A, and p-p collisions to investigate nuclear matter under extreme conditions. A wide variety of probes, sensitive to all timescales, are used to study systematic variations with species and energy as well as to measure the spin structure of the nucleon. Designing for the needs of the heavy-ion and polarized-proton programs has produced a detector with unparalleled capabilities. PHENIX measures electron and muon pairs, photons, and hadrons with excellent energy and momentum resolution. The detector consists of a large number of subsystems that are discussed in other papers in this volume. The overall design parameters of the detector are presented. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 2. |
- Alcorn, J, et al.
(författare)
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Basic instrumentation for Hall A at Jefferson Lab
- 2004
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 522:3, s. 294-346
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Tidskriftsartikel (refereegranskat)abstract
- The instrumentation in Hall A at the Thomas Jefferson National Accelerator Facility was designed to study electro-and photo-induced reactions at very high luminosity and good momentum and angular resolution for at least one of the reaction products. The central components of Hall A are two identical high resolution spectrometers, which allow the vertical drift chambers in the focal plane to provide a momentum resolution of better than 2 x 10(-4). A variety of Cherenkov counters, scintillators and lead-glass calorimeters provide excellent particle identification. The facility has been operated successfully at a luminosity well in excess of 10(38) CM-2 s(-1). The research program is aimed at a variety of subjects, including nucleon structure functions, nucleon form factors and properties of the nuclear medium. (C) 2003 Elsevier B.V. All rights reserved.
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| 3. |
- Wijesooriya, K, et al.
(författare)
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Polarization measurements in high-energy deuteron photodisintegration
- 2001
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 86:14, s. 2975-2979
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the recoil proton polarization for the d(γ⃗,p⃗)n reaction at θc.m. = 90° for photon energies up to 2.4 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. The induced polarization py vanishes above 1 GeV, contrary to meson-baryon model expectations, in which resonances lead to large polarizations. However, the polarization transfer Cx does not vanish above 1 GeV, inconsistent with hadron helicity conservation. Thus, we show that the scaling behavior observed in the d(γ,p)ncross sections is not a result of perturbative QCD. These data should provide important tests of new nonperturbative calculations in the intermediate energy regime.
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| 4. |
- Dutta, D, et al.
(författare)
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Nuclear transparency with the gamma n ->pi(-)p process in He-4
- 2003
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 68:2: 021001
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the nuclear transparency of the fundamental process gamman-->pi(-)p in He-4. These measurements were performed at Jefferson Lab in the photon energy range of 1.6-4.5 GeV and at theta(cm)(pi)=70degrees and 90degrees. These measurements are the first of their kind in the study of nuclear transparency in photoreactions. They also provide a benchmark test of Glauber calculations based on traditional models of nuclear physics. The transparency results suggest deviations from the traditional nuclear physics picture. The momentum transfer dependence of the measured nuclear transparency is consistent with Glauber calculations that include the quantum chromodynamics phenomenon of color transparency.
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| 5. |
- Schlegel, C, et al.
(författare)
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K-isomers in very neutron-rich nuclei around mass 180
- 2000
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Ingår i: Physica Scripta. Topical Issues. - 0281-1847. ; T88, s. 72-76
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Tidskriftsartikel (refereegranskat)abstract
- gamma-spectroscopy methods have been used to search for microsecond isomers among the fragmentation products of a 1 GeV/nucleon Pb-208 beam. In particular the population of the known K-pi = 35/2(-) isomer in W-179 has been investigated and several new isomeric decays have been found for neutron rich nuclei in the A approximate to 180-200 mass region. The ground state band of the neutron rich N = 116 system of W-190 has been identified for the first time and we discuss its structure in comparison to neighboring systems.
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| 6. |
- Schulte, EC, et al.
(författare)
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High energy angular distribution measurements of the exclusive deuteron photodisintegration reaction
- 2002
-
Ingår i: Physical Review C (Nuclear Physics). - : American Physical Society. - 0556-2813 .- 1089-490X. ; 66:4
-
Tidskriftsartikel (refereegranskat)abstract
- The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to E-gamma=2.4 GeV, the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results.
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| 7. |
- Wijesooriya, K, et al.
(författare)
-
Polarization measurements in neutral pion photoproduction
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:3
-
Tidskriftsartikel (refereegranskat)abstract
- We present measurements of the recoil proton polarization for the H-1((γ) over right arrow,(p) over right arrow)pi(0) reaction for theta(c.m.)(pi) = 60degrees-135degrees and for photon energies up to 4.1 GeV. These are the first data in this reaction for polarization transfer with circularly polarized photons. Various theoretical models are compared with the results. No evidence for hadron helicity conservation is observed. Models that employ factorization are not favored. It appears from the strong angular dependence of the induced polarization at photon energies of 2.5 and 3.1 GeV that a relatively high spin resonance or background amplitude might exist in this energy region.
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| 8. |
- Zhu, LY, et al.
(författare)
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Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium
- 2003
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Ingår i: Physical Review Letters. - 1079-7114. ; 91:2: 022003
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Tidskriftsartikel (refereegranskat)abstract
- We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma)greater than or similar to3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.
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| 9. |
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| 10. |
- Bearden, IG, et al.
(författare)
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Particle production in central Pb+Pb collisions at 158A GeV/c
- 2002
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 66:4
-
Tidskriftsartikel (refereegranskat)abstract
- The NA44 experiment has measured single-particle inclusive spectra for charged pions, kaons, and protons as a function of transverse mass near midrapidity in 158A GeV/c Pb+Pb collisions. From the particle mass dependence of the observed m(T) distributions, we are able to deduce a value of about 120 MeV for the temperature at thermal freeze-out. From the observed ratios of the rapidity densities, we find values of the chemical potentials for light and strange quarks and a chemical freeze-out temperature of approximately 140 MeV.
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| 11. |
- Bearden, IG, et al.
(författare)
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Deuteron and triton production with high energy sulphur and lead beams
- 2002
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 23:2, s. 237-247
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Tidskriftsartikel (refereegranskat)abstract
- Proton and deuteron production has been observed in S+S and S+Pb collisions at 200 A-GeV and in Pb+Pb reactions at 158 A-GeV at the CERN SPS accelerator. For Pb+Pb triton production was also measured. The p and d spectra as well as the p and t spectra were observed in similar rapidity ranges and over similar ranges of transverse momenta per nucleon, making it possible to interpret the cross sections of the composite particles in terms of coalescence mechanisms. Volumes of homogeneity were extracted and compared to pion-pair HBT interferometry results. Special attention is given to the dependence on transverse mass, centrality and rapidity.
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| 12. |
- Lindmark, F, et al.
(författare)
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H6D polymorphism in macrophage-inhibitory cytokine-1 gene associated with prostate cancer
- 2004
-
Ingår i: Journal of the National Cancer Institute. - Umea Univ, Dept Radiat Sci Oncol, S-90187 Umea, Sweden. Karolinska Inst, Dept Med Epidemiol & Biostat, Stockholm, Sweden. Umea Univ Hosp, Dept Urol & Androl, S-90185 Umea, Sweden. Wake Forest Univ, Sch Med, Ctr Human Genomics, Winston Salem, NC 27109 USA. Johns Hopkins Med Inst, Dept Urol, Baltimore, MD 21205 USA. : OXFORD UNIV PRESS INC. - 0027-8874 .- 1460-2105. ; 96:16, s. 1248-1254
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Tidskriftsartikel (refereegranskat)abstract
- Background: Accumulating epidemiologic and molecular evidence suggest that inflammation is an important component in the etiology of prostate cancer. Macrophage-inhibitory cytokine-1 (MIC-1), a member of the transforming growth factor beta superfamily, is thought to play an important role in inflammation by regulating macrophage activity. We examined whether sequence variants in the MIC-1 gene are associated with the risk of prostate cancer. Methods: The study population, a population-based case-control study in Sweden, consisted of 1383 prostate cancer case patients and 780 control subjects. From 94 of the control subjects, we constructed gene-specific haplotypes of MIC-1 and identified four haplotype-tagging single-nucleotide polymorphisms (SNPs): Exon1+25 (V9L), Exon1+142 (S48T), IVS1+1809, and Exon2+2423 (H6D). All study subjects were genotyped for the four SNPs, and conditional logistic regression analysis was used to estimate odds ratios (ORs) with 95% confidence intervals (CIs). Results: A statistically significant difference (P = .006) in genotype frequency was observed for the nonsynonymous change H6D) (histidine to aspartic acid at position 6) between prostate cancer patients and control subjects. Carriers of the GC genotype, which results in the H6D change, experienced a lower risk of sporadic prostate cancer (OR = 0.80, 95% CI = 0.66 to 0.97) and of familial prostate cancer (OR = 0.61, 95% CI = 0.42 to 0.89) than the CC genotype carriers. In the study population, the proportion of prostate cancer cases attributable to the CC genotype was 7.2% for sporadic cancer and 19.2% for familial cancer. None of the other SNPs or haplotypes was associated with prostate cancer. Conclusion: This study shows an association between a nonsynonymous change (H6D) in the MIC-1 gene and prostate cancer. This finding supports the hypothesis that genetic variation in the inflammatory process contributes to prostate cancer susceptibility.
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| 13. |
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| 14. |
- Zhu, Bin, et al.
(författare)
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Innovative low temperature SOFCs and advanced materials
- 2003
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Ingår i: Journal of Power Sources. - 0378-7753 .- 1873-2755. ; 118:02-jan, s. 47-53
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Tidskriftsartikel (refereegranskat)abstract
- High ionic conductivity, varying from 0.01 to 1 S cm(-1) between 300 and 700 degreesC, has been achieved for the hybrid and nano-ceriacomposite electrolyte materials, demonstrating a successful application for advanced low temperature solid oxide fuel cells (LTSOFCs). The LTSOFCs were constructed based on these new materials. The performance of 0.15-0.25 W cm(-2) was obtained in temperature region of 320400 degreesC for the ceria-carbonate composite electrolyte, and of 0.35-0.66 W cm(-2) in temperature region of 500-600 degreesC for the ceria-lanthanum oxide composites. The cell could even function at as low as 200 degreesC. The cell has also undergone a life test for several months. A two-cell stack was studied, showing expected performance successfully. The excellent LTSOFC performance is resulted from both functional electrolyte and electrode materials. The electrolytes are two phase composite materials based on the oxygen ion and proton conducting phases, or two rare-earth oxides. The electrodes used were based on the same composite material system having excellent compatibility with the electrolyte. They are highly catalytic and conductive thus creating the excellent performances at low temperatures. These innovative LT materials and LTSOFC technologies would open the door for wide applications, not only for stationary but also for mobile power sources.
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| 15. |
- Björkqvist, Maria, et al.
(författare)
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Human neutrophil lipocalin : normal levels and use as a marker for invasive infection in the newborn
- 2004
-
Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 93:4, s. 534-539
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To evaluate human neutrophil lipocalin (HNL) as a marker of neonatal invasive infection and determine the normal serum levels of HNL in newborns. METHODS: HNL is released from neutrophil granulocytes and is regarded as a specific marker of neutrophil activity. In 81 newborns < or = 28 d of age with signs of infection on a total of 87 occasions, HNL and C-reactive protein (CRP) were measured at inclusion and on the three following days. As controls, term healthy newborns were recruited at birth (cord blood, n = 45) and at ages 3-5 d (n = 46). Serum HNL was measured by a radioimmunoassay. RESULTS: 25/87 episodes were classified as infection and 62 as non-proven infection. HNLmax was significantly higher in the infected group (mean 587.6 microg/l) than in the non-proven infected group (mean 217.7 microg/, p < 0.001). HNL peaked at inclusion, 1 d earlier than CRP. In the healthy controls. HNL was the same at 3-5 d of age as at birth (mean 82.4-81.7 microg/l) and similar to normal adult levels. CONCLUSIONS: The release of HNL is not increased in healthy newborns at birth, but neonatal neutrophils rapidly release HNL upon microbial stimulation in vivo. HNL might be useful as an early marker of neonatal infection.
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| 16. |
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Petrovic, S, et al.
(författare)
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SLC26A7: a basolateral Cl-/HCO3- exchanger specific to intercalated cells of the outer medullary collecting duct
- 2004
-
Ingår i: American journal of physiology. Renal physiology. - : American Physiological Society. - 1931-857X .- 1522-1466. ; 286:1, s. F161-F169
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Tidskriftsartikel (refereegranskat)abstract
- The outer medullary collecting duct (OMCD) plays an important role in bicarbonate reabsorption and acid-base regulation. An apical V-type H+-ATPase and a basolateral [Formula: see text] exchanger, located in intercalated cells of OMCD, mediate the bicarbonate reabsorption. Here we report the identification of a new basolateral [Formula: see text] exchanger in OMCD intercalated cells in rat kidney. Northern hybridizations demonstrated the predominant expression of this transporter, also known as SLC26A7, in the outer medulla, with lower expression levels in the inner medulla. SLC26A7 was recognized as a ∼90-kDa band in the outer medulla by immunoblot analysis and was localized on the basolateral membrane of a subset of OMCD cells by immunocytochemical staining. No labeling was detected in the cortex. Double-immunofluorescence labeling with the aquaporin-2 and SLC26A7 antibodies or anion exchanger-1 and SLC26A7 antibodies identified the SLC26A7-expressing cells as α-intercalated cells. Functional studies in oocytes demonstrated that increasing the osmolality of the media (to simulate the physiological milieu in the medulla) increased the [Formula: see text] exchanger activity mediated via SLC26A7 by about threefold ( P < 0.02 vs. normal condition). We propose that SLC26A7 is a basolateral [Formula: see text] exchanger in intercalated cells of the OMCD and may play an important role in bicarbonate reabsorption in medullary collecting duct.
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| 21. |
- Prakobphol, A, et al.
(författare)
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Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340.
- 2000
-
Ingår i: The Journal of biological chemistry. - 0021-9258 .- 1083-351X. ; 275:51, s. 39860-6
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Tidskriftsartikel (refereegranskat)abstract
- Salivary agglutinin is a high molecular mass component of human saliva that binds Streptococcus mutans, an oral bacterium implicated in dental caries. To study its protein sequence, we isolated the agglutinin from human parotid saliva. After trypsin digestion, a portion was analyzed by matrix-assisted laser/desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), which gave the molecular mass of 14 unique peptides. The remainder of the digest was subjected to high performance liquid chromatography, and the separated peptides were analyzed by MALDI-TOF/post-source decay; the spectra gave the sequences of five peptides. The molecular mass and peptide sequence information showed that salivary agglutinin peptides were identical to sequences in lung (lavage) gp-340, a member of the scavenger receptor cysteine-rich protein family. Immunoblotting with antibodies that specifically recognized either lung gp-340 or the agglutinin confirmed that the salivary agglutinin was gp-340. Immunoblotting with an antibody specific to the sialyl Le(x) carbohydrate epitope detected expression on the salivary but not the lung glycoprotein, possible evidence of different glycoforms. The salivary agglutinin also interacted with Helicobacter pylori, implicated in gastritis and peptic ulcer disease, Streptococcus agalactiae, implicated in neonatal meningitis, and several oral commensal streptococci. These results identify the salivary agglutinin as gp-340 and suggest it binds bacteria that are important determinants of either the oral ecology or systemic diseases.
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| 22. |
- Seth, A, et al.
(författare)
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Gene expression profiling of ductal carcinomas in situ and invasive breast tumors
- 2003
-
Ingår i: Anticancer research. - 1791-7530. ; 23:3A, s. 2043-2051
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Tidskriftsartikel (refereegranskat)abstract
- Comparative and functional genomics are powerful tools to advance the understanding of the molecular basis of cancer. It is believed that genes are epigenetically regulated and, thus, each tumor type and stage will be characterized by a gene expression fingerprint. In this study we identified genes that are differentially expressed in ductal carcinoma in situ and invasive ductal carcinoma of the breast. To isolate genes that are associated with progression of breast cancer we performed differential display and subtractive cloning procedures using matched RNA from normal and tumor tissue. cDNA microarray analysis generated gene expression profiles typical of the transition front in situ to invasive breast cancer when we used mRAA extracted from a case of low-to intermediate-grade DCIS and a case of high-grade DC1S/IDC. cDNAs from these samples were the probes in a cDNA microarray hybridization to 9183 unique cDAAs representing 8507 genes. Signals from both transcriptomes were obtained for 8083 genes, and the balanced differential expression values between pure DCIS and DCIS/invasive tumors revealed 303 distinct cDNAs with a ratio of > 2. Interferon inducible genes were found to be expressed at the highest level in the pure DCIS sample. Genes most abundantly expressed in the invasive tumor were immunoglobulin heavy constant gamma 3 and calgranulin B. Further analysis of RNA and protein expression in breast tumor cell lines and patient tissue samples revealed that: IGFBP-rP1 is down-regulated in invasive tumors whereas cyclin I protein is regulated by ubiquitination and is associated with ER-negative breast cancers. Conclusion: The known and novel genes discussed here represent targets for molecular characterization during breast cancer development as well as,for designing novel strategies for diagnosis and treatment.
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| 23. |
- Ström, Valter, et al.
(författare)
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A novel and rapid method for quantification of magnetic nanoparticle-cell interactions using a desktop susceptometer
- 2004
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 15:5, s. 457-466
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Tidskriftsartikel (refereegranskat)abstract
- Activated endothelial cells (EC) are attractive prime targets for specific drug delivery using drug-carrying magnetic nanoparticles. In order to accomplish EC targeting, the interaction between magnetic particles and resting as well as activated endothelial cells must be characterized and quantified, because it will influence particle biodistribution, circulation half-time, and targeting efficacy. Here, we have quantified in vitro the interaction (adhesion/phagocytosis) between human endothelial cells and magnetite (Fe3O4) particles carrying different surface coatings with varying degrees of hydrophilicity and surface charge. Almost no adhesion was observed (about 1% or less) for three out of five particle types carrying plain dextran, carboxyl-substituted poly(ethylene glycol) and silica C18 coatings. In contrast, carboxyl-functionalized dextran and poly(ethylene glycol)-coated particles adhered or were phagocytosed to a considerable degree (58 and 26%, respectively). These clear and accurate results were obtained by measuring the magnetic response, i.e. magnetic susceptibility, from different fractions of the cell cultures as a means of determining the concentration of magnetic particles. Visible light and electron microscopy confirmed the magnetic quantification. To meet the need for a rapid yet sensitive instrument, we have developed a desktop magnetic susceptometer especially adapted for liquid samples or particles in a suspension. Despite its very high sensitivity, it is easy to operate and requires but a few seconds for a measurement. We also describe the construction and operation of this instrument.
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| 24. |
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| 25. |
- Abraham, T., et al.
(författare)
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Polyelectrolyte-mediated interaction between similarly charged surfaces : Role of divalent counter ions in tuning surface forces
- 2001
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 17:26, s. 8321-8327
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Tidskriftsartikel (refereegranskat)abstract
- The effects of divalent salts (CaCl2, MgCl2 and BaCl2) in promoting the adsorption of weakly charged polyelectrolyte (polyacrylic acid), PAA, Mw similar to 250000 g/mol) on mica surfaces and their role in tuning the nature of interactions between such adsorbed polyelectrolyte layers were studied using the interferometric surface forces apparatus. With mica surfaces in 3 mM MgCl2 solutions at pH similar to8.0-9.0, the addition of 10 ppm PAA resulted in a long-range attractive bridging force and a short-range repulsive steric force. This force profile indicates a low surface coverage and weak adsorption. The range of the force can be related to the characteristic length scale R-G of polyelectrolyte chains using a scaling description. An increase of the PAA concentration to 50 ppm changed the attractive force profile to a monotonic, long-range repulsive interaction extending up to 600 Angstrom due to the increased surface coverage of polyelectrolyte chains on the mica surfaces. Comparison of the measured forces with a scaling mean field model suggests that the adsorbed polyelectrolyte chains are stretched, which eventually give rise to the polyelectrolyte brush like structure. When the mica surfaces were preincubated in 3 mM CaCl2 at pH similar to8.0-9.0, in contrast to the case of 3 MM MgCl2, the addition of 10 ppm PAA resulted in a more complex force profile: long-range repulsive forces extending up to 800 Angstrom followed by an attractive force regime and a second repulsive force regime at shorter separations. The long-range electrosteric forces can be attributed to strong adsorption of polyelectrolyte chains on mica surfaces (high surface coverage) which is facilitated by the presence of Ca2+ ions, while the intermediate range attractive forces can be ascribed to Ca2+ assisted bridging between adsorbed polyelectrolyte chains. Also interesting is to note various relaxation processes present in this system. In contrast to both MgCl2 and CaCl2 systems, with mica surfaces in 3 mM BaCl2 solution at pH similar to8.0-9.0, the addition of 10 ppm PAA resulted in precipitation of polyelectrolyte chains on mica surfaces, resulting in an extremely long-range monotonic repulsive force profile. In summary, our study showed that divalent counterions (Mg2+, Ca2+, and Ba2+) exhibit significantly different behavior in promoting PAA adsorption on mica surfaces, modifying and controlling various surface interactions.
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| 26. |
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| 27. |
- Bergdahl, Andreas, et al.
(författare)
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Cholesterol depletion impairs vascular reactivity to endothelin-1 by reducing store-operated Ca2+ entry dependent on TRPC1.
- 2003
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Ingår i: Circulation Research. - 0009-7330. ; 93:9, s. 839-847
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Tidskriftsartikel (refereegranskat)abstract
- The reactivity of the vascular wall to endothelin-1 (ET-1) is influenced by cholesterol, which is of possible importance for the progression of atherosclerosis. To elucidate signaling steps affected, the cholesterol acceptor methyl-ß-cyclodextrin (mßcd, 10 mmol/L) was used to manipulate membrane cholesterol and disrupt caveolae in intact rat arteries. In endothelium-denuded caudal artery, contractile responsiveness to 10 nmol/L ET-1 (mediated by the ETA receptor) was reduced by mßcd and increased by cholesterol. Neither ligand binding nor colocalization of ETA and caveolin-1 was affected by mßcd. Ca2+ inflow via store-operated channels after depletion of intracellular Ca2+ stores was reduced in mßcd-treated caudal arteries, as shown by Mn2+ quench rate and intracellular [Ca2+] response. Expression of TRPC1, 3, and 6 was detected by reverse transcriptase–polymerase chain reaction, and colocalization of TRPC1 with caveolin-1 was reduced by mßcd, as seen by immunofluorescence. Part of the contractile response to ET-1 was inhibited by Ni2+ (0.5 mmol/L) and by a TRPC1 blocking antibody. In the basilar artery, exhibiting less store-operated channel activity than the caudal artery, ET-1–induced contractions were insensitive to the TRPC1 blocking antibody and to mßcd. Increased store-operated channel activity in basilar arteries after organ culture correlated with increased sensitivity of ET-1 contraction to mßcd. These results suggest that cholesterol influences vascular reactivity to ET-1 by affecting the caveolar localization of TRPC1.
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| 28. |
- Berndtsson, R., et al.
(författare)
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Solar-climatic relationship and implications for hydrology
- 2001
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Ingår i: Nordic Hydrology. - 0029-1277. ; 32:2, s. 65-84
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Tidskriftsartikel (refereegranskat)abstract
- Research during the latest years has indicated a significant connection between climate and solar activity. Specifically, a relationship between Northern Hemisphere air temperature and sunspot cycle length (SCL) has been shown. By using monthly SCL and land air temperature from 1753-1990 (238 years) we show that this relationship also holds for a single observation point in south of Sweden. Using data after 1850 yields a statistically significant linear correlation of 0.54 between SCL and mean temperature. Furthermore, we show that there are indications of a low-dimensional chaotic component in both SCL and the interconnected mean land air temperature. This has important implications for hydrology and water resources applications. By pure definition of chaos this means that it is virtually impossible to make long-term predictions of mean temperature. Similarly, because of the strong connection between temperature and many hydrological components, it is probable that also long-term water balance constituents may follow chaotic trajectories. Long-term projections of water resources availability may therefore be impossible. Repeated short-term predictions may, however, still be viable. We exemplify this by showing a technique to predict interpolated mean temperature 6 and 12 months ahead in real time with encouraging results. Improving the technique further may be possible by including information on the SCL attractor. To summarize, research into the possible existence of chaotic components in hydrological processes should be an important task for the next years to come.
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| 29. |
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| 30. |
- Brooks, Andrew J, et al.
(författare)
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The interdomain region of dengue NS5 protein that binds to the viral helicase NS3 contains independently functional importin beta 1 and importin alpha/beta-recognized nuclear localization signals
- 2002
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 277:39, s. 36399-36407
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Tidskriftsartikel (refereegranskat)abstract
- Dengue virus NS5 protein is a multifunctional RNA-dependent RNA polymerase that is essential for virus replication. We have shown previously that the 37- amino acid interdomain spacer sequence (residues (369)X(2)KKX(14)KKKX(11)RKX(3)405) of Dengue2 NS5 contains a functional nuclear localization signal (NLS). In this study, beta-galactosidase fusion proteins carrying point mutations of the positively charged residues or truncations of the interdomain linker region (residues 369-389 or residues 386-405) were analyzed for nuclear import and importin binding activities to show that the N-terminal part of the linker region (residues 369-389, a/bNLS) is critical for nuclear localization and is recognized with high affinity by the conventional NLS-binding importin alpha/beta heterodimeric nuclear import receptor. We also show that the importin beta-binding site (residues 320-368, bNLS) adjacent to the a/bNLS, previously identified by yeast two-hybrid analysis, is functional as an NLS, recognized with high affinity by importin beta, and able to target beta-galactosidase to the nucleus. Intriguingly, the bNLS is highly conserved among Dengue and related flaviviruses, implying a general role for the region and importin beta in the infectious cycle.
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| 31. |
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| 32. |
- Enfors, Sven-Olof, et al.
(författare)
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Physiological responses to mixing in large scale bioreactors
- 2001
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Ingår i: Journal of Biotechnology. - 0168-1656 .- 1873-4863. ; 85:2, s. 175-185
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Tidskriftsartikel (refereegranskat)abstract
- Escherichia coli fed-batch cultivations at 22 m(3) scale were compared to corresponding laboratory scale processes and cultivations using a scale-down reactor furnished with a high-glucose concentration zone to mimic the conditions in a feed zone of the large bioreactor. Formate accumulated in the large reactor, indicating the existence of oxygen limitation zones. It is suggested that the reduced biomass yield at large scale partly is due to repeated production/reassimilation of acetate from overflow metabolism and mixed acid fermentation products due to local moving zones with oxygen limitation. The conditions that generated mixed-acid fermentation in the scale-down reactor also induced a number of stress responses, monitored by analysis of mRNA of selected stress induced genes. The stress responses were relaxed when the cells returned to the substrate limited and oxygen sufficient compartment of the reactor. Corresponding analysis in the large reactor showed that the concentration of mRNA of four stress induced genes was lowest at the sampling port most distant from the feed zone. It is assumed that repeated induction/relaxation of stress responses in a large bioreactor may contribute to altered physiological properties of the cells grown in large-scale bioreactor. Flow cytometric analysis revealed reduced damage with respect to cytoplasmic membrane potential and integrity in cells grown in the dynamic environments of the large scale reactor and the scale-down reactor.
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| 33. |
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| 34. |
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| 35. |
- Hansen-Schwartz, J, et al.
(författare)
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Subarachnoid hemorrhage-induced upregulation of the 5-HT1B receptor in cerebral arteries in rats
- 2003
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Ingår i: Journal of Neurosurgery. - 0022-3085. ; 99:1, s. 115-120
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Tidskriftsartikel (refereegranskat)abstract
- Object. Cerebral vasospasm following subarachnoid hemorrhage (SAH) leads to reduced blood flow in the brain. Inspired by organ culture-induced changes in the receptor phenotype of cerebral arteries, the authors investigated possible changes in the 5-hydroxytryptamine (HT) receptor phenotype after experimental SAH. Methods. Experimental SAH was induced in rats by using an autologous prechiasmatic injection of arterial blood. Two days later, the middle cerebral artery (MCA), posterior communicating artery (PCoA), and basilar artery (BA) were harvested and examined functionally with the aid of a sensitive in vitro pharmacological method and molecularly by performing quantitative real-time reverse transcription-polymerase chain reaction (PCR). In the MCA and BA the 5-HT1B receptor was upregulated, as determined through both functional and molecular analysis. In response to selective 5-HT1 receptor agonists both the negative logarithm of the 50% effective concentration was increased (one log unit in the MCA and one half unit in the BA), as was the agonist's potency (increased by 50% in the MCA and doubled in the BA). In addition, the authors found an approximately fourfold increase in the number of copies of messenger RNA coding for the 5-HT1B receptor as determined by quantitative real-time PCR. In the PCoA no upregulation of the 5-HT1B receptor was observed. Conclusions. Changes in the receptor phenotype in favor of contractile receptors may well represent the end stage in a sequence of events leading from SAH to the actual development of cerebral vasospasm. Insight into the mechanism of upregulation may provide new targets for developing specific treatment against cerebral vasospasm.
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| 36. |
- He, Sailing, et al.
(författare)
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A simple analytical method for calculating the leakage loss of a buried rectangular waveguide
- 2004
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Ingår i: Journal of Optics. A, Pure and applied optics. - : IOP Publishing. - 1464-4258 .- 1741-3567. ; 6:1, s. 57-62
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Tidskriftsartikel (refereegranskat)abstract
- A simple and efficient analytical method is presented for studying leaky modes in a buried rectangular waveguide on a high-refractive-index substrate. The cross-sectional profile of the refractive index for the buried rectangular waveguide is decomposed into three parts. The two main parts correspond to two independent multilayered slab waveguide structures and the remaining part is treated as a small perturbation term. The contributions from all three parts to the leakage loss are given analytically. Numerical results are presented and compared with those calculated with the semi-vectorial finite difference method. Fast speed, satisfactory accuracy and simplicity are the main advantages of the present method.
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| 37. |
- He, X., et al.
(författare)
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Separation and purification of puerarin using beta-cyclodextrin-coupled agarose gel media
- 2004
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Ingår i: J. Chromatogr. A. ; 1022:1-2, s. 77-82
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Tidskriftsartikel (refereegranskat)abstract
- The isoflavonoid puerarin, a well-known traditional Chinese drug, has been purified in one step from an extract of Radix puerariae (root of the plant Pueraria lobata) by adsorption chromatography on an epichlorohydrin polymerized beta-cyclodextrin ligand coupled to brominated allyl-group substituted Sepharose HP. Acetic acid (10%) was used as the mobile phase and the optimum loading capacity was around 1.2 mg crude extract/ml packed gel. The purity of the collected puerarin was about 98% with a recovery of about 62%.
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| 38. |
- Hicks, R. G., et al.
(författare)
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Strong supramolecular-based magnetic exchange in pi-stacked radicals. Structure and magnetism of a hydrogen-bonded verdazyl radical : hydroquinone molecular solid
- 2001
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Ingår i: Journal of the American Chemical Society. ; 123:29, s. 7154-7159
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Tidskriftsartikel (refereegranskat)abstract
- The X-ray crystal structure and magnetic properties of a molecular crystal consisting of 1,5-dimethyl-3-(2-pyridyl)-6-oxoverdazyl radical and hydroquinone (pyvd:hq) are presented. The structure contains a two-dimensional network of hydrogen bonds involving the hydroquinones and the pyridine ring of the pyvd radical. The radicals adopt an unusual head-over-tail (antiparallel) jr-stacked array perpendicular to the hydrogen-bonded planes. The variable-temperature magnetic susceptibility data can be modeled using a one-dimensional antiferromagnetic chain model, with J = -58 cm(-1). The strength of the magnetic coupling is very unusual because there are no close intermolecular radical-radical contacts to provide conventional pathways for magnetic interactions. A pathway for coupling is proposed involving the mediation of magnetic exchange interactions between radical centers by the pyridine rings. Density functional calculations on the pyvd radical, as well as aggregates thereof based on the X-ray structure, have been employed in attempts to understand the possible mechanisms by which the strong magnetic interactions are achieved.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Lemiale, Franck, et al.
(författare)
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Enhanced mucosal immunoglobulin A response of intranasal adenoviral vector human immunodeficiency virus vaccine and localization in the central nervous system.
- 2003
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Ingår i: Journal of Virology. - 0022-538X. ; 77:18, s. 10078-87
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Tidskriftsartikel (refereegranskat)abstract
- Replication-defective adenovirus (ADV) vectors represent a promising potential platform for the development of a vaccine for AIDS. Although this vector is typically administered intramuscularly, it would be desirable to induce mucosal immunity by delivery through alternative routes. In this study, the immune response and biodistribution of ADV vectors delivered by different routes were evaluated. ADV vectors expressing human immunodeficiency virus type 1 (HIV-1) Gag, Pol, and Env were delivered intramuscularly or intranasally into mice. Intranasal immunization induced greater HIV-specific immunoglobulin A (IgA) responses in mucosal secretions and sera than in animals with intramuscular injection, which showed stronger systemic cellular and IgG responses. Administration of the vaccine through an intranasal route failed to overcome prior ADV immunity. Animals exposed to ADV prior to vaccination displayed substantially reduced cellular and humoral immune responses to HIV antigens in both groups, though the reduction was greater in animals immunized intranasally. This inhibition was partially overcome by priming with a DNA expression vector expressing HIV-1 Gag, Pol, and Env before boosting with the viral vector. Biodistribution of recombinant adenovirus (rADV) vectors administered intranasally revealed infection of the central nervous system, specifically in the olfactory bulb, possibly via retrograde transport by olfactory neurons in the nasal epithelium, which may limit the utility of this route of delivery of ADV vector-based vaccines.
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| 45. |
- Li, H. N., et al.
(författare)
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Electronic structure of Yb2.75C60
- 2003
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 68:16
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Tidskriftsartikel (refereegranskat)
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| 46. |
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| 47. |
- Li, K., et al.
(författare)
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MBE-based SiGe/Si heterojunction multilayer structures
- 2001
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Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 227-228, s. 744-748
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, SiGe/Si multilayer heterostructures prepared by molecular beam epitaxy (MBE) are described with the aim of manufacturing SiGe heterojunction bipolar transistors (HBTs). Based on the simulations made by Medici, device structures have been designed and grown. The quality of the MBE layered structures has been characterized by reflection high-energy electron diffraction, X-ray diffraction, secondary ion mass spectrometry and spreading resistance. Furthermore, SiGe-HBTs have been fabricated. Promising DC and RF results of processed HBT devices have been obtained. © 2001 Elsevier Science B.V.
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| 48. |
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| 49. |
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