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A micromethod for quantitation of debrisoquine and 4-hydroxydebrisoquine in urine by liquid chromatography

Pereira,V.A.; Auler Jr.,J.O.; Carmona,M.J.; Mateus,F.H.; Lanchote,V.L.; Breimer,D.D.; Santos,S.R.C.J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2000 Português
Relevância na Pesquisa
435.69945%
We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred µl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 µg/ml). The 5-µm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lexcitation = 210 nm and lemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2% (D) and 5.3/8.2% (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax®, po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine...

Effects of Streptococcus thermophilus TH-4 on intestinal mucositis induced by the chemotherapeutic agent 5-Fluorouracil (5-FU)

Whitford, E.; Cummins, A.; Butler, R.; Prisciandaro, L.; Fauser, J.; Yazbek, R.; Lawrence, A.; Cheah, K.; Wright, T.; Lymn, K.; Howarth, G.
Fonte: Landes Bioscience Publicador: Landes Bioscience
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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435.69945%
Beneficial bacteria (probiotics) and probiotic-derived factors have the potential to ameliorate disorders of the intestine. The aim of this study was to compare live Streptococcus thermophilus TH-4 (TH-4), dead TH-4 and TH-4 supernatant in rats treated with 5-Fluorouracil. Rats were randomly allocated to five treatment groups (n=8-10): Saline+Water; 5-FU+Skim Milk; 5-FU+Live TH-4; 5-FU+Supernatant TH-4; and 5-FU+Dead TH-4. 5-FU (150mg.kg(-1)) was administered by a single intraperitoneal injection on day 0; animals were killed on day 4. Treatments were administered daily from days -2 to 3 via oro-gastric gavage. Metabolic parameters were measured daily. Blood was obtained by cardiac puncture, and intestinal tissues removed for quantitative and qualitative histological assessment, including: villous height and area; crypt depth and area, mitotic count and crypt fission; biochemical determination of sucrase and myeloperoxidase (MPO) activity; and disease severity scoring. One-way ANOVA statistical analyses were conducted for the majority of outcome measures. Live TH-4 significantly reduced disease severity score by 13% (p< 0.05), and partially normalised mitotic counts compared with 5-FU+Skim milk controls. Live and supernatant TH-4 reduced crypt fission by 69% and 48% (p< 0.05)...

Effect of placental restriction and neonatal exendin-4 treatment on postnatal growth, adult body composition and in vivo glucose metabolism in the sheep

Liu, H.; Schultz, C.G.; De Blasio, M.J.; Peura, A.M.; Heinemann, G.K.; Harryanto, H.; Hunter, D.S.; Wooldridge, A.L.; Kind, K.L.; Giles, L.C.; Simmons, R.A.; Owens, J.A.; Gatford, K.L.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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434.92305%
Intrauterine growth restriction (IUGR) increases risks of adult type 2 diabetes (T2D) and obesity. Neonatal exendin-4 treatment can prevent diabetes in the IUGR rat, but whether this will be effective in a species where the pancreas is more mature at birth, is unknown. We therefore evaluated the effects of neonatal exendin-4 administration after experimental restriction of placental and fetal growth on growth and adult metabolic outcomes in sheep. Body composition, glucose tolerance and insulin secretion and sensitivity were assessed in singleton-born adult sheep from control (CON; n = 6 F, 4 M) and placentally restricted pregnancies (PR; n = 13 F, 7 M), and in sheep from PR pregnancies that were treated with exendin-4 as neonates (daily s.c. injections of 1 nmol.kg(-1) exendin-4; PR+EX-4; n = 11 F, 7 M). Placental restriction reduced birth weight (by 29%) and impaired glucose tolerance in the adult, but did not affect adult adiposity, insulin secretion, or insulin sensitivity. Neonatal exendin-4 suppressed growth during treatment followed by delayed catch-up growth and unchanged adult adiposity. Neonatal exendin-4 partially restored glucose tolerance in PR progeny but did not affect insulin secretion or sensitivity. Although the effects on glucose tolerance are promising...

Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

CMS Collaboration; Adair, A.; Akgun, B.; Ecklund, K.M.; Geurts, F.J.M.; Li, W.; Michlin, B.; Padley, B.P.; Redjimi, R.; Roberts, J.; Zabel, J.
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Artigo de Revista Científica
Português
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435.09266%
Production of prompt J/ψ meson pairs in proton-proton collisions at √s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb−1. The two J/ψ mesons are fully reconstructed via their decays into μ + μ − pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ψ transverse momentum (p T J/ψ ) and rapidity (|y J/ψ |): |y J/ψ | < 1.2 for p T J/ψ > 6.5 GeV/c; 1.2 < |y J/ψ | < 1.43 for a p T threshold that scales linearly with |y J/ψ | from 6.5 to 4.5 GeV/c; and 1.43 < |y J/ψ | < 2.2 for p T J/ψ > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/ψ pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/ψ polarization imply modifications to the cross section ranging from −31% to +27%.

Isolation and characterization of ovine IGFBP-4: protein purification and cDNA sequence

CARR, J.M.; GRANT, P.A.; FRANCIS, G.L.; OWENS, J.A.; WALLACE, J.C.; WALTON, P.E.
Fonte: BioScientifica Publicador: BioScientifica
Tipo: Artigo de Revista Científica
Publicado em //1994 Português
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437.9116%
Three different molecular mass forms of IGF-binding proteins (IGFBPs) were purified from ovine plasma by IGF-I affinity chromatography and reverse-phase HPLC: a 46 kDa doublet and 29 kDa and 24 kDa forms. Amino-terminal sequence analysis confirmed that these proteins were ovine (o)IGFBP-3 (46 kDa) and two molecular size variants of oIGFBP-4. oIGFBP-3 and the 29 kDa form of oIGFBP-4 were shown to be N-glycosylated. Isoelectric points were determined to be at approximately pH 6 for oIGFBP-3 and at pH 7 and pH 7.5 for the 29 and 24 kDa forms of oIGFBP-4 respectively. The two different molecular mass variants of oIGFBP-4 had similar IGF-binding properties. Compared with human IGFBP-3 and oIGFBP-3, the two variants of oIGFBP-4 exhibited lower relative binding to amino-terminally modified IGF-I analogues in a competitive IGF-binding assay. The full protein sequence of oIGFBP-4, as deduced from the cDNA sequence, showed a high degree of identity with rat (90%), human (96%) and bovine (98%) IGFBP-4. The cDNA sequence also showed homology over regions of the 3' non-coding sequence, particularly in comparison with bovine IGFBP-4 (96%). Northern analysis of mRNA for oIGFBP-4 indicated a 2.6 kb major transcript and two minor transcripts of approximately 2.1 and 1.8 kb. oIGFBP-4 mRNA transcripts were detected in adult ewe liver > kidney > lung >> heart and also in several fetal tissues...

Warm and Dense Molecular Gas in the N159 Region: 12CO J=4–3 and 13CO J=3–2 Observations with NANTEN2 and ASTE

Bernard, Jean-Philippe; Rubio, Mónica; Yamamoto, Hiroaki; Yamaguchi, Nobuyuki; Wong, Tony; Whitney, Barbara; Tatematsu, Ken’ichi; Kawamura, Akiko; Bertoldi, Frank; Ikeda, Masafumi; Stutzki, Jürgen; Klein, Uli; Benz, Arnold; Gordon, Karl D.; Burton, Mi
Fonte: Universidade do Chile Publicador: Universidade do Chile
Tipo: Artículo de revista
Português
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437.8878%
New 12CO J=4–3 and 13CO J=3–2 observations of the N159 region, an active site of massive star formation in the Large Magellanic Cloud, have been made with the NANTEN2 and ASTE sub-mm telescopes, respectively. The 12CO J=4–3 distribution is separated into three clumps, each associated with N159W, N159E and N159S. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the 12CO J=1–0, J=2–1, J=3–2, and J=7–6 as well as the isotope transitions of 13CO J=1–0, J=2–1, J=3–2, and J=4–3. The 13CO J=3–2 data are newly taken for the present work. The temperatures and densities are determined to be 70-80K and 3×103 cm−3 in N159W and N159E and 30K and 1.6×103 cm−3 in N159S. Observed 12CO J=2–1 and 12CO J=1–0 intensities toward N159W and N159E are weaker than expected from calculations of uniform temperature and density, suggesting that low-excitation foreground gas causes self-absorption. These results are compared with the star formation activity based on the data of young stellar clusters and HII regions as well as the mid-infrared emission obtained with the Spitzer MIPS. The N159E clump is associated with embedded cluster(s) as observed at 24 μm by the Spitzer MIPS and the derived high temperature...

Genetics and physiology of cell wall polysaccharides in the model C₄ grass, Setaria viridis spp; Genetics and physiology of cell wall polysaccharides in the model C(4) grass, Setaria viridis spp

Ermawar, R.A.; Collins, H.M.; Byrt, C.S.; Henderson, M.; O'Donovan, L.A.; Shirley, N.J.; Schwerdt, J.G.; Lahnstein, J.; Fincher, G.B.; Burton, R.A.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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436.378%
BACKGROUND: Setaria viridis has emerged as a model species for the larger C4 grasses. Here the cellulose synthase (CesA) superfamily has been defined, with an emphasis on the amounts and distribution of (1,3;1,4)-β-glucan, a cell wall polysaccharide that is characteristic of the grasses and is of considerable value for human health. METHODS: Orthologous relationship of the CesA and Poales-specific cellulose synthase-like (Csl) genes among Setaria italica (Si), Sorghum bicolor (Sb), Oryza sativa (Os), Brachypodium distachyon (Bradi) and Hordeum vulgare (Hv) were compared using bioinformatics analysis. Transcription profiling of Csl gene families, which are involved in (1,3;1,4)-β-glucan synthesis, was performed using real-time quantitative PCR (Q-PCR). The amount of (1,3;1,4)-β-glucan was measured using a modified Megazyme assay. The fine structures of the (1,3;1,4)-β-glucan, as denoted by the ratio of cellotriosyl to cellotetraosyl residues (DP3:DP4 ratio) was assessed by chromatography (HPLC and HPAEC-PAD). The distribution and deposition of the MLG was examined using the specific antibody BG-1 and captured using fluorescence and transmission electron microscopy (TEM). RESULTS: The cellulose synthase gene superfamily contains 13 CesA and 35 Csl genes in Setaria. Transcript profiling of CslF...

IRAC Observations of CO J=4-3 High-Velocity Cloud in the 30 Doradus Complex in the Large Magellanic Cloud

Kim, H-S.; Kim, S.; Bak, J. Y.; Garcia, M.; Brandl, B.; Xiao, K.; Walsh, W.; Smith, R. C.; Youn, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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532.8943%
We compare the CO 2-1 observations against previously taken CO 4-3 observations and analyze the spatial distribution of young stellar objects (YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus complex. Both peaks of CO 2-1 and 4-3 emitting clouds coincide with the densest region of the filaments where multiple shells are colliding. We find that the YSO's are clustered in the southern ridge of the warm and dense molecular gas clouds traced by CO J=4-3, indicating a filamentary structure of star formation throughout the 30 Doradus. We also find that some of Class I YSO's candidates which are likely to be associated with a high-velocity component of CO 4-3 emitting clouds are present. This is a bona fide place where the triggered star formation had happened and newly formed stars may have produced such a high-velocity outflow interacting with the surrounding molecular cloud material.; Comment: 17 pages, 7 figures, Submitted to ApJ

CO and Dust in PSS2322+1944 at a redshift of 4.12

Cox, P.; Omont, A.; Djorgovski, S. G.; Bertoldi, F.; Pety, J.; Carilli, C. L.; Isaac, K. G.; Beelen, A.; McMahon, R. G.; Castro, S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/03/2002 Português
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436.93047%
Using the IRAM interferometer we have detected J=4-3 and 5-4 CO line emission toward the radio quiet quasar PSS2322+1944. At a redshift of z_CO=4.1199 this is the fourth and strongest detection of CO at z>4. The velocity-integrated CO J=4-3 and J=5-4 line fluxes are 4.21+-0.40 and 3.74+-0.56 Jy km/s, and the linewidth is ~300 km/s. The CO J=10-9 line was searched for but not detected with an upper intensity limit of 30 mJy. The 1.35 mm (250 mum rest wavelength) continuum flux density is 7.5+-1.3 mJy, in agreement with previous bolometer measurements at 1.2 mm with the 30-m IRAM telescope. The 3mm (580 mum rest wavelength) continuum is not detected with a 3 sigma upper limit of 0.7mJy. We also report observations of the 450 mum continuum in PSS2322+1944 using the SCUBA array at the JCMT. The quasar was detected with a 450 mum flux density of 79+-19mJy. At the angular resolution of 4.8" x 2.1" at 1.3mm and 6.2" x 4.9" at 3.2 mm, the interferometer observations do not show evidence of spatial extension in the continuum or CO line emission. Assuming no gravitational magnification, we estimate a molecular gas mass of ~2.5x10^11 M_sun. The molecular gas is warm (40-100 K) and dense (10^3.5-10^4.1 cm^-3). The infrared-to-CO luminosity ratio is ~185 L_sun/(K km/s pc^2)...

Dense Gas Tracers and Star Formation Laws in Active Galaxies: APEX Survey of HCN J=4-3, HCO+ J=4-3, and CS J=7-6

Zhang, Zhi-Yu; Gao, Yu; Henkel, Christian; Zhao, Yinghe; Wang, Junzhi; Menten, Karl M.; Guesten, Rolf
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 05/02/2014 Português
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436.70273%
We report HCN J=4-3, HCO+ J=4-3, and CS J=7-6 observations in 20 nearby star-forming galaxies with the Acatama Pathfinder EXperiment 12-m telescope. Combined with 4 HCN, 3 HCO+, and 4 CS detections in literature, we probe the empirical link between the luminosity of molecular gas (L_gas) and that of infrared emission (L_IR), up to the highest gas densities (10^6 - 10^8 cm-3) that have been probed so far. For nearby galaxies with large radii, we measure the IR luminosity within the submm beam-size (14"-18") to match the molecular emission. We find linear slopes for L_CS76-L_IR and L_HCN43-L_IR, and a slightly super-linear slope for L_HCO+43-L_IR. The correlation of L_CS76-L_IR even extends over eight orders of luminosity magnitude down to Galactic dense cores, with a fit of log(L_IR)=1.00(\pm 0.01) \times log(L_CS76) + 4.03(\pm 0.04). Such linear correlations appear to hold for all densities >10^4 cm-3, and indicate that star formation rate is not related to free-fall time scale for dense molecular gas.; Comment: 7 pages, 3 figures. Comments and suggestions are welcome. Accepted by ApJL

Warm and Dense Molecular Gas in the N159 Region: 12CO J=4-3 and 13CO J=3-2 Observations with NANTEN2 and ASTE

Mizuno, Yoji; Kawamura, Akiko; Onishi, Toshikazu; Minamidani, Tetsuhiro; Muller, Erik; Yamamoto, Hiroaki; Hayakawa, Takahiro; Mizuno, Norikazu; Mizuno, Akira; Stutzki, Jurgen; Pineda, Jorge L.; Klein, Uli; Bertoldi, Frank; Koo, Bon-Chul; Rubio, Monica; Bu
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 01/10/2009 Português
Relevância na Pesquisa
435.6181%
New 12CO J=4-3 and 13CO J=3-2 observations of the N159 region in the Large Magellanic Cloud have been made. The 12CO J=4-3 distribution is separated into three clumps. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the 12CO as well as the isotope transitions of 13CO. The temperatures and densities are determined to be ~70-80K and ~3x10^3 cm-3 in N159W and N159E and ~30K and ~1.6x10^3 cm-3 in N159S. These results are compared with the star formation activity. The N159E clump is associated with embedded cluster(s) as observed at 24 micron and the derived high temperature is explained as due to the heating by these sources. The N159E clump is likely responsible for a dark lane in a large HII region by the dust extinction. The N159W clump is associated with embedded clusters mainly toward the eastern edge of the clump only. These clusters show offsets of 20"-40" from the 12CO J=4-3 peak and are probably responsible for heating indicated by the derived high temperature. The N159W clump exhibits no sign of star formation toward the 12CO J=4-3 peak position and its western region. We suggest that the N159W peak represents a pre-star-cluster core of ~105M_sol which deserves further detailed studies. Note that recent star formation took place between N159W and N159E as indicated by several star clusters and HII regions...

Dense Molecular Gas Excitation at High Redshift: Detection of HCO+(J=4-3) Emission in the Cloverleaf Quasar

Riechers, Dominik A.; Walter, Fabian; Carilli, Christopher L.; Cox, Pierre; Weiss, Axel; Bertoldi, Frank; Menten, Karl M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/11/2010 Português
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435.85203%
We report the detection of HCO+(J=4-3) emission in the Cloverleaf Quasar at z=2.56, using the IRAM Plateau de Bure Interferometer. HCO+ emission is a star formation indicator similar to HCN, tracing dense molecular hydrogen gas (n(H2) ~= 10^5 cm^-3) within star-forming molecular clouds. We derive a lensing-corrected HCO+(J=4-3) line luminosity of L'(HCO+(4-3)) = (1.6+/-0.3) x 10^9 (mu_L/11)^-1 K km/s pc^2, which corresponds to only 48% of the HCO+(J=1=0) luminosity, and <~4% of the CO(J=3-2) luminosity. The HCO+ excitation thus is clearly subthermal in the J=4-3 transition. Modeling of the HCO+ line radiative transfer suggests that the HCO+ emission emerges from a region with physical properties comparable to that exhibiting the CO line emission, but 2x higher gas density. This suggests that both HCO+ and CO lines trace the warm, dense molecular gas where star formation actively takes place. The HCO+ lines have only ~2/3 the width of the CO lines, which may suggest that the densest gas is more spatially concentrated. In contrast to the z=3.91 quasar APM08279+5255, the dense gas excitation in the Cloverleaf is consistent with being purely collisional, rather than being enhanced by radiative processes. Thus, the physical properties of the dense gas component in the Cloverleaf are consistent with those in the nuclei of nearby starburst galaxies. This suggests that the conditions in the dense...

Probing X-ray irradiation in the nucleus of NGC 1068 with observations of high-J lines of dense gas tracers

Perez-Beaupuits, J. P.; Spaans, M.; van der Tak, F. F. S.; Aalto, S.; Garcia-Burillo, S.; Fuente, A.; Usero, A.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/06/2009 Português
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435.68188%
With the incorporation of high-J molecular lines, we aim to constrain the physical conditions of the dense gas in the central region of the Seyfert 2 galaxy NGC 1068 and to determine signatures of the AGN or the starburst contribution. We used the James Clerk Maxwell Telescope to observe the J=4-3 transition of HCN, HNC, and HCO+, as well as the CN N_J=2_{5/2}-1_{3/2} and N_J=3_{5/2}-2_{5/2}, in NGC 1068. We estimate the excitation conditions of HCN, HNC, and CN, based on the line intensity ratios and radiative transfer models. We find that the bulk emission of HCN, HNC, CN, and the high-J HCO+ emerge from dense gas n(H_2)>=10^5 cm^-3). However, the low-J HCO+ lines (dominating the HCO+ column density) trace less dense (n(H_2)<10^5 cm^-3) and colder (T_K<=20 K) gas, whereas the high-J HCO+ emerges from warmer (>30 K) gas than the other molecules. The HCO+ J=4-3 line intensity, compared with the lower transition lines and with the HCN J=4-3 line, support the influence of a local XDR environment. The estimated N(CN)/N(HCN)~1-4 column density ratios are indicative of an XDR/AGN environment with a possible contribution of grain-surface chemistry induced by X-rays or shocks.; Comment: Main text: 8 pages, 5 tables, 1 figure. Appendix: 7 pages...

AST/RO Observations of CO J=7-6 and J=4-3 Emission toward the Galactic Center Region

Kim, Sungeun; Martin, Christopher L.; Stark, Antony A.; Lane, Adair P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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437.4577%
We present position-velocity strip maps of the Galactic Center region in the CO J=7-6 and J=4-3 transitions observed with the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) located at Amundsen-Scott South Pole Station. Emission from the two rotational transitions of 12^CO was mapped at b=0 deg for 3.5 deg > l > -1.5 deg, on a 1' grid with a FWHM beamsize of 58'' at 806 GHz and 105'' at 461 GHz. Previous observations of CO J=4-3 (Martin et al., in preparation) and CI (Ojha et al. 2001) emission from this region show that these lines are distributed in a manner similar to CO J=1-0 (Stark et al. 1987); the (CO J=4-3)/(CO J=1-0) line ratio map is almost featureless across the entire Galactic Center region. In contrast, the CO J=7-6 emission from the Galactic Center is strongly peaked toward the Sgr A and Sgr B molecular complexes. A Large Velocity Gradient (LVG) analysis shows that aside from the two special regions Sgr A and Sgr B, the photon-dominated regions within a few hundred parsecs of the Galactic Center are remarkably uniform in mean density and kinetic temperature at n = 2500 to 4000 cm^{-3} and T=30 to 45K. The (CO J=7-6)/(CO J=4-3) line temperature ratios near Sgr B are a factor of two higher than those observed in the nuclear region of the starburst galaxy M82 (Mao et al. 2000)...

ALMA Detection of the Vibrationally Excited HCN J=4-3 Emission Line in the AGN-Hosting Luminous Infrared Galaxy IRAS 20551-4250

Imanishi, Masatoshi; Nakanishi, Kouichiro
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/08/2013 Português
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434.6955%
We present results from our ALMA Cycle 0 observations, at the frequencies around the HCN, HCO+, and HNC J=4-3 transition lines, of the luminous infrared galaxy IRAS 20551-4250 at z=0.043, which is known to host an energetically important obscured AGN. In addition to the targeted HCN, HCO+, and HNC J=4-3 emission lines, two additional strong emission lines are seen, which we attribute to H2S and CH3CN(+CCH). The HCN-to-HCO+ J=4-3 flux ratio (~0.7) is higher than in the other starburst-dominated galaxy (~0.2) observed in our ALMA Cycle 0 program. We tentatively (~5 sigma) detected the vibrationally excited (v2=1) HCN J=4-3 (l=1f) emission line, which is important for testing an infrared radiative pumping scenario for HCN. This is the second detection of this molecular transition in external galaxies. The most likely reason for this detection is not only the high flux of this emission line, but also the small molecular line widths observed in this galaxy, suggesting that vibrational excitation of HCN may be relatively common in AGN-hosting galaxies.; Comment: 11 pages, 5 figures, accepted for publication in AJ

AST/RO Observations of CO J=4-3 Emission from the N44 Complex in the Large Magellanic Cloud

Kim, Sungeun; Walsh, Wilfred; Xiao, Kecheng
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 07/06/2004 Português
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435.85203%
We present Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) observations of 12CO J=4-3 and C I emission in the N44 H II complex in the Large Magellanic Cloud. We detected strong 12CO J=4-3 emission toward the H II region called as N44BC, which is located on the rim of an expanding giant shell in the N44 region. Analysis with a photodissociation region (PDR) model showed that the 12CO J=4-3 emitting cloud is very dense, with n ~ 10^5 cm^-3. We also note that there is a high-velocity component associated with the 12CO J=4-3 emission. This probably originates from molecular material accelerated as a result of the motion induced by the expanding giant shell surrounding LH47 in the N44 complex. We found that the kinetic energy of this high-velocity gas observed in the CO J=4-3 emission toward the rim of the expanding H II shell is at least an order of magnitude higher than the kinetic energy derived for the H I and H II gas in this region.; Comment: 11 pages, 5 figures, submitted to ApJ

Warm and Dense Molecular Gas in the N 159 Region: ^(12)CO J = 4–3 and ^(13)CO J = 3–2 Observations with NANTEN2 and ASTE

Mizuno, Yoji; Kawamura, Akiko; Onishi, Toshikazu; Minamidani, Testuhiro; Muller, Erik; Yamamoto, Hiroaki; Hayakawa, Takahiro; Mizuno, Norikazu; Mizuno, Akira; Stutzki, Jürgen; Pineda, Jorge L.; Klein, Uli; Bertoldi, Frank; Koo, Bon-Chul; Rubio, Monica; B
Fonte: Astronomical Society of Japan Publicador: Astronomical Society of Japan
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 25/02/2010 Português
Relevância na Pesquisa
438.22297%
New ^(12)CO J = 4–3 and ^(13)CO J = 3–2 observations of the N 159 region, an active site of massive star formation in the Large Magellanic Cloud, have been made with the NANTEN2 and ASTE submillimeter telescopes, respectively. The ^(12)CO J = 4–3 distribution is separated into three clumps, each associated with N 159 W, N 159 E, and N 159 S. These new measurements toward the three clumps are used in coupled calculations of molecular rotational excitation and line radiation transfer, along with other transitions of the ^(12)CO J = 1–0, J = 2–1, J = 3–2, and J = 7–6 as well as the isotope transitions of ^(13)CO J = 1–0, J = 2–1, J = 3–2, and J = 4–3. The ^(13)CO J = 3–2 data were newly taken for the present work. The temperatures and densities were found to be ~70–80 K and ~3 × 10^3 cm^(-3) in N 159 W and N 159 E, and ~30 K and ~1.6 × 10^3 cm^(-3) in N 159 S. These results were compared with the star-formation activity based on data of young stellar clusters and HII regions as well as midinfrared emission obtained with the Spitzer MIPS. The N 159 E clump is associated with cluster(s) embedded, as observed at 24 μm by the Spitzer MIPS, and the derived high temperature, 80 K, is interpreted as being heated by these sources. The N 159 E clump is likely to be responsible for a dark lane in a large HII region by dust extinction. On the other hand...

Measurement of prompt J/ψ pair production in pp collisions at √s = 7 Tev

Khachatryan, V.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Di Marco, E.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Rogan, C.; Spiropulu, M.; Timciuc, V.; Wilkinson, R.; Xie, S.; Zhu, R. Y.; Dias, F. A.; Dubinin, M.
Fonte: Springer Publicador: Springer
Tipo: Article; PeerReviewed Formato: application/pdf; application/pdf
Publicado em 17/09/2014 Português
Relevância na Pesquisa
435.02555%
Production of prompt J/ψ meson pairs in proton-proton collisions at √s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb^(−1). The two J/ψ mesons are fully reconstructed via their decays into μ^+μ^− pairs. This observation provides for the first time access to the high-transverse-momentum region of J/ψ pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/ψ transverse momentum (pT^(J/ψ)) and rapidity (|y^(J/ψ)|): |y^(J/ψ)| < 1.2 for p_T^(J/ψ) > 6.5 GeV/c; 1.2 < |y^(J/ψ)| < 1.43 for a pT threshold that scales linearly with |y^(J/ψ)| from 6.5 to 4.5 GeV/c; and 1.43 < |y^(J/ψ)| < 2.2 for p_T^(J/ψ) > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/ψ pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/ψ polarization imply modifications to the cross section ranging from −31% to +27%.

Dense Molecular Gas Excitation at High Redshift: Detection of HCO^+(J = 4 → 3) Emission in the Cloverleaf Quasar

Riechers, Dominik A.; Walter, Fabian; Carilli, Christopher L.; Cox, Pierre; Weiss, Axel; Bertoldi, Frank; Menten, Karl M.
Fonte: American Astronomical Society Publicador: American Astronomical Society
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em 01/01/2011 Português
Relevância na Pesquisa
435.22086%
We report the detection of HCO^+(J = 4 → 3) emission in the Cloverleaf Quasar at z = 2.56, using the IRAM Plateau de Bure Interferometer. HCO^+ emission is a star formation indicator similar toHCN, tracing densemolecular hydrogen gas (n(H_2) ≃ 10^5 cm^(−3)) within star-forming molecular clouds. We derive a lensing-corrected HCO^+(J = 4 → 3) line luminosity of L'_(HCO)^+(4–3) = (1.6 ± 0.3) × 10^9 (μ_L/11)^(−1)K km s^(−1) pc^2, which corresponds to only 48% of the HCO^+(J = 1 → 0) luminosity, and ≲4% of the CO(J = 3→2) luminosity. The HCO^+ excitation thus is clearly subthermal in the J = 4 → 3 transition. Modeling of the HCO^+ line radiative transfer suggests that the HCO^+ emission emerges from a region with physical properties comparable to that exhibiting the CO line emission, but 2 × higher gas density. This suggests that both HCO^+ and CO lines trace the warm, dense molecular gas where star formation actively takes place. The HCO^+ lines have only ~2/3 the width of the CO lines, which may suggest that the densest gas is more spatially concentrated. In contrast to the z = 3.91 quasar APM 08279+5255, the dense gas excitation in the Cloverleaf is consistent with being purely collisional, rather than being enhanced by radiative processes. Thus...

Dense Gas Tracers and Star Formation Laws in Active Galaxies: APEX Survey of HCN J = 4 → 3, HCO^+ J = 4 → 3, and CS J=7 → 6

Zhang, Zhi-Yu; Gao, Yu; Henkel, Christian; Zhao, Yinghe; Wang, Junzhi; Menten, Karl M.; Güsten, Rolf
Fonte: American Astronomical Society Publicador: American Astronomical Society
Tipo: Article; PeerReviewed Formato: application/pdf; application/pdf
Publicado em 01/04/2014 Português
Relevância na Pesquisa
437.09996%
We report HCN J = 4 → 3, HCO^+ J = 4 → 3, and CS J = 7 → 6 observations in 20 nearby star-forming galaxies with the Atacama Pathfinder EXperiment 12 m telescope. Combined with four HCN, three HCO^+, and four CS detections from the literature, we probe the empirical link between the luminosity of molecular gas L'_gas and that of infrared emission (L_(IR), up to the highest gas densities (~10^6 cm^(–3)) that have been probed so far. For nearby galaxies with large radii, we measure the IR luminosity within the submillimeter beam size (14"-18") to match the molecular emission. We find linear slopes for L'_(CSJ=7-6)-L_(IR) and L'_(HCNJ=4-3)-L_(IR), and a slightly super-linear slope for L'_(HCO^+J=4-3)-L_(IR). The correlation of L'_(CSJ=7-6)-L_(IR) even extends over eight orders of luminosity magnitude down to Galactic dense cores, with a fit of log(L_(IR)) =1.00(± 0.01)×log L'_(CSJ=7-6) + 4.03(± 0.04). Such linear correlations appear to hold for all densities >10^4 cm^(–3), and indicate that star formation rate is not related to the free-fall timescale for dense molecular gas.