| 21. |
- Zhang, Zijian, et al.
(författare)
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Impact of Mountains in Southern China on the Eocene Climates of East Asia
- 2022
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Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 127:17
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Tidskriftsartikel (refereegranskat)abstract
- Inconsistencies in the Eocene climates of East Asia have been revealed in both geological studies and simulations. Several earlier reconstructions showed an arid zonal band in mid-latitude China, but others showed a humid climate in the same region. Moreover, previous Eocene modeling studies have demonstrated that climate models can simulate both scenarios in China. Therefore, it is essential to investigate the cause of this model spread. We conducted a series of experiments using Norwegian Earth System Model 1-F and examined the impact of mountains in Southern China on the simulated Eocene climate. These mountains, including the Gangdese and Southeast Mountains, are located along the main path of water vapor transport to East Asia. Our results reveal that the Southeast Mountains play the dominant role in controlling the simulated precipitation in Eastern China during the Eocene. When the heights of the Southeast Mountains exceed similar to 2,000 m, an arid zonal band appears in mid-latitude China, whereas humid climates appear in Eastern China when the elevation of the Southeast Mountains is relatively low.
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| 22. |
- Zheng, Xubin, et al.
(författare)
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Drug exposure and susceptibility of second-line drugs correlate with treatment response in patients with multidrug-resistant tuberculosis : a multicentre prospective cohort study in China
- 2022
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Ingår i: European Respiratory Journal. - : European Respiratory Society. - 0903-1936 .- 1399-3003. ; 59:3
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Tidskriftsartikel (refereegranskat)abstract
- Background Understanding the impact of drug exposure and susceptibility on treatment response of multidrug-resistant tuberculosis (MDR-TB) will help to optimise treatment. This study aimed to investigate the association between drug exposure, susceptibility and response to MDR-TB treatment. Methods Drug exposure and susceptibility for second-line drugs were measured for patients with MDR-TB. Multivariate analysis was applied to investigate the impact of drug exposure and susceptibility on sputum culture conversion and treatment outcome. Probability of target attainment was evaluated. Random Forest and CART (Classification and Regression Tree) analysis was used to identify key predictors and their clinical targets among patients on World Health Organization-recommended regimens. Results Drug exposure and corresponding susceptibility were available for 197 patients with MDR-TB. The probability of target attainment was highly variable, ranging from 0% for ethambutol to 97% for linezolid, while patients with fluoroquinolones above targets had a higher probability of 2-month culture conversion (56.3% versus 28.6%; adjusted OR 2.91, 95% CI 1.42-5.94) and favourable outcome (88.8% versus 68.8%; adjusted OR 2.89, 95% CI 1.16-7.17). Higher exposure values of fluoroquinolones, linezolid and pyrazinamide were associated with earlier sputum culture conversion. CART analysis selected moxifloxacin area under the drug concentration-time curve/minimum inhibitory concentration (AUC(0-24)h/MIC) of 231 and linezolid AUC(0-24)h/MIC of 287 as best predictors for 6-month culture conversion in patients receiving identical Group A-based regimens. These associations were confirmed in multivariate analysis. Conclusions Our findings indicate that target attainment of TB drugs is associated with response to treatment. The CART-derived thresholds may serve as targets for early dose adjustment in a future randomised controlled study to improve MDR-TB treatment outcome.
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| 23. |
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| 24. |
- Zhu, Jiazheng, et al.
(författare)
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SN 2017egm : A Helium-rich Superluminous Supernova with Multiple Bumps in the Light Curves
- 2023
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 949:1
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Tidskriftsartikel (refereegranskat)abstract
- When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He i lambda 10830 and four He i absorption lines in the optical. Consequently, we classify SN 2017egm as a member of an emerging population of helium-rich SLSNe-I (i.e., SLSNe-Ib). We also present our late-time photometric observations. By combining them with archival data, we analyze high-cadence ultraviolet, optical, and near-infrared light curves spanning from early pre-peak (similar to-20 days) to late phases (similar to+300 days). We obtain its most complete bolometric light curve, in which multiple bumps are identified. None of the previously proposed models can satisfactorily explain all main light-curve features, while multiple interactions between the ejecta and circumstellar material (CSM) may explain the undulating features. The prominent infrared excess with a blackbody luminosity of 10(7)-10(8) L (circle dot) detected in SN 2017egm could originate from the emission of either an echo of a pre-existing dust shell or newly formed dust, offering an additional piece of evidence supporting the ejecta-CSM interaction model. Moreover, our analysis of deep Chandra observations yields the tightest-ever constraint on the X-ray emission of an SLSN-I, amounting to an X-ray-to-optical luminosity ratio less than or similar to 10(-3) at late phases (similar to 100-200 days), which could help explore its close environment and central engine.
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