| 1. |
- Güsten, R., et al.
(författare)
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APEX - The Atacama Pathfinder Experiment
- 2006
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6267 I
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Konferensbidrag (refereegranskat)abstract
- APEX, the Atacama Pathfinder Experiment, has been successfully commissioned and is in operation now. This novel submillimeter telescope is located at 5107 m altitude on Llano de Chajnantor in the Chilean High Andes, on what is considered one of the world's outstanding sites for submillimeter astronomy. The primary reflector with 12 m diameter has been carefully adjusted by means of holography. Its surface smoothness of 17-18 μm makes APEX suitable for observations up to 200 μm, through all atmospheric submm windows accessible from the ground.
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| 2. |
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| 3. |
- Korn, A. J., et al.
(författare)
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HE 1327-2326, AN UNEVOLVED STAR WITH [Fe/H] <-5.0. III. DOES ITS ATMOSPHERE REFLECT ITS NATAL COMPOSITION?
- 2009
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 698:1, s. 410-416
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Tidskriftsartikel (refereegranskat)abstract
- Based on spectroscopic constraints derived from nonlocal thermodynamic equilibrium line formation, we explore the likely range of stellar parameters (T-eff and log g) for the hyper-metal-poor (HMP) star HE 1327-2326. Combining the constraints from Balmer line profiles and the Ca I/II ionization equilibrium, a subgiant stage of evolution is indicated. This result is further supported by spectrophotometric observations of the Balmer jump. If a higher T-eff value was used (as favored by some photometric calibrations), the spectroscopic analysis would indicate a turnoff-point stage of evolution. Using a stellar-structure code that treats the effects of atomic diffusion throughout the star in detail, we evolve a low-mass model star to reach the Hertzsprung-Russell-diagram position of HE 1327-2326 after roughly 13 Gyr. While the surface abundances are modified significantly (by more than 1 dex for the case of uninhibited diffusion), such corrections cannot resolve the discrepancy between the abundance inferred from the nondetection of the Li I resonance line at 6707 angstrom and the Wilkinson Microwave Anisotropy Probe based primordial lithium abundance. As there are numerous processes that can destroy lithium, any cosmological interpretation of a lower-than-expected lithium abundance at the lowest metallicities will have to await sample sizes of unevolved HMP stars that are 1 order of magnitude larger. The situation remains equally inconclusive concerning atomic-diffusion corrections. Here, attempts have to be made to better constrain internal mixing processes, both observationally and by means of sophisticated modeling. With constraints on additional mixing processes taken from a recent globular-cluster study, the likeliest scenario is that HE 1327-2326's surface abundances have undergone mild depletion (of order 0.2 dex).
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| 4. |
- Perez, A. E. Garcia, et al.
(författare)
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A new sample of extremely/ultra metal-poor stars
- 2008
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Ingår i: Physica Scripta. - 0031-8949 .- 1402-4896. ; T133, s. 014036-
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Tidskriftsartikel (refereegranskat)abstract
- A sample of 30 very metal-poor stars from the Hamburg-European Southern Observatory (ESO) objective-prism survey have been observed at high spectral resolution at the Very Large Telescope (VLT) using the Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed stars are very interesting not only because of their very low iron content, approximately four orders of magnitude lower than the solar value, but also because we detected the neutral lithium resonance line at 670.8 nm. Hydrogen lines suggest that the two observed stars have effective temperatures around 6000-6250K and according to isochrones, they are either on the main-sequence or on the subgiant branch, in which case they would probably be the most metal-poor dwarfs or warm subgiants with lithium detections known. These detections would allow to determine more accurately the slope of the trend of the lithium abundance with [Fe/H] than was possible with samples of unevolved stars restricted to higher metallicities.
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| 7. |
- Chang-Claude, Jenny, et al.
(författare)
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Age at menarche and menopause and breast cancer risk in the International BRCA1/2 Carrier Cohort Study
- 2007
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Ingår i: Cancer Epidemiology Biomarkers and Prevention. - 1055-9965. ; 16:4, s. 740-746
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Tidskriftsartikel (refereegranskat)abstract
- Background: Early menarche and late menopause are important risk factors for breast cancer, but their effects on breast cancer risk in BRCA1 and BRCA2 carriers are unknown. Methods: We assessed breast cancer risk in a large series of 1,187 BRCA1 and 414 BRCA2 carriers from the International BRCA1/2 Carrier Cohort Study. Rate ratios were estimated using a weighted Cox-regression approach. Results: Breast cancer risk was not significantly related to age at menopause {hazard ratio [HR] for menopause below age 35 years, 0.60 [95% confidence interval (95% CI), 0.25-1.44]; 35 to 40 years, 1.15 [0.65-2.04]; 45 to 54 years, 1.02 [0.65-1.60]; ≥55 years, 1.12 [0.12-5.02], as compared with premenopausal women}. However, there was some suggestion of a reduction in risk after menopause in BRCA2 carriers. There was some evidence of a protective effect of oophorectomy (HR, 0.56; 95% CI, 0.29-1.09) and a significant trend of decreasing risk with increasing time since oophorectomy, but no apparent effect of natural menopause. There was no association between age at menarche and breast cancer risk, nor any apparent association with the estimated total duration of breast mitotic activity. Conclusions: These results are consistent with other observations suggesting a protective effect of oophorectomy, similar in relative effect to that in the general population. The absence of an effect of age at natural menopause is, however, not consistent with findings in the general population and may reflect the different natural history of the disease in carriers.
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| 8. |
- Denton, Christopher P., et al.
(författare)
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Recombinant human anti-transforming growth factor beta 1 antibody therapy in systemic sclerosis - A multicenter, randomized, placebo-controlled phase I/II trial of CAT-192
- 2007
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 56:1, s. 323-333
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To evaluate CAT-192, a recombinant human antibody that neutralizes transforming growth factor beta 1 (TGF beta 1), in the treatment of early-stage diffuse cutaneous systemic sclerosis (dcSSc). Methods. Patients with SSc duration of < 18 months were randomly assigned to the placebo group or to 1 of 3 CAT-192 treatment groups: 10 mg/kg, 5 mglkg, 0.5 mg/kg. Infusions were given on day 0 and weeks 6, 12, and 18. The primary objective of this study was to evaluate the safety, tolerability, and pharmacokinetics of CAT-192. Secondary outcomes included the modified Rodnan skin thickness score (MRSS), the Scleroderma Health Assessment Questionnaire, assessment of organ-based disease, serum levels of soluble interleukin-2 receptor, collagen propeptides (N propeptide of type I [PINP] and type III collagen), and tissue levels of messenger RNA for procollagens I and III and for TGF beta 1 and TGF beta 2. Results. Forty-five patients were enrolled. There was significant morbidity and mortality, including I death in the group receiving 0.5 mg/kg of CAT-192 and 3 deaths in the group receiving 5 mg/kg of CAT-192. There were more adverse events and more serious adverse events in patients receiving CAT-192 than in those receiving placebo, although these events were not more frequent in the high-dose treatment group. The MRSS improved in all groups during the study, but there was no evidence of a treatment effect for CAT-192. Improvement in the MRSS correlated with the disease duration (r = -0.54, P = 0.0008). Changes in the PINP level from baseline correlated with changes in the MRSS (r = 0.37, P = 0.027). Conclusion. We report the first evaluation of a systemically administered and repeatedly dosed anti-TGF beta 1 drug. In this pilot study, CAT-192, in doses up to 10 mg/kg, showed no evidence of efficacy. The utility of clinical and biochemical outcome measures and the feasibility of multicenter trials of early dcSSc were confirmed.
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| 9. |
- Düringer, Caroline, et al.
(författare)
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Agonist-specific patterns of beta(2)-adrenoceptor responses in human airway cells during prolonged exposure.
- 2009
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Ingår i: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 158, s. 169-179
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: beta(2)-Adrenoceptor agonists (beta(2)-agonists) are important bronchodilators used in the treatment of asthma and chronic obstructive pulmonary disease. At the molecular level, beta(2)-adrenergic agonist stimulation induces desensitization of the beta(2)-adrenoceptor. In this study, we have examined the relationships between initial effect and subsequent reduction of responsiveness to restimulation for a panel of beta(2)-agonists in cellular and in vitro tissue models. Experimental approach: beta(2)-Adrenoceptor-induced responses and subsequent loss of receptor responsiveness were studied in primary human airway smooth muscle cells and bronchial epithelial cells by measuring cAMP production. Receptor responsiveness was compared at equi-effective concentrations, either after continuous incubation for 24 h or after a 1 h pulse exposure followed by a 23 h washout. Key findings were confirmed in guinea pig tracheal preparations in vitro. Key results: There were differences in the reduction of receptor responsiveness in human airway cells and in vitro guinea pig trachea by a panel of beta(2)-agonists. When restimulation occurred immediately after continuous incubation, loss of responsiveness correlated with initial effect for all agonists. After the 1 h pulse exposure, differences between agonists emerged, for example isoprenaline and formoterol induced the least reduction of responsiveness. High lipophilicity was, to some extent, predictive of loss of responsiveness, but other factors appeared to be involved in determining the relationships between effect and subsequent loss of responsiveness for individual agonists. Conclusions and implications: There were clear differences in the ability of different beta(2) agonists to induce loss of receptor responsiveness at equi-effective concentrations.
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| 10. |
- Gosch, M., et al.
(författare)
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Parallel dual-color fluorescence cross-correlation spectroscopy using diffractive optical elements
- 2005
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Ingår i: Journal of Biomedical Optics. - : SPIE-Intl Soc Optical Eng. - 1083-3668 .- 1560-2281. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Dual-color cross-correlation spectroscopy allows the detection and quantification of labeled biomolecules at ultra-low concentrations, whereby the sensitivity of the assay correlates with the measurement time. We now describe a parallel multifocal dual-color spectroscopic configuration employing multiple avalanche photodiodes and hardware correlators. Cross-correlation curves are obtained from several dual-color excitation foci simultaneously. Multifocal dual-color excitation is achieved by splitting each of two laser beams (488 and 633 nm) into four sub-beams with the help of two 2 X 2 fan-out diffractive optical elements (DOES), and subsequent superposition of the two sets of four foci. The fluorescence emission from double-labeled biomolecules is detected by two 2 x 2 fiber arrays.
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