Browsing by Subject "EPISODES"

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  • Du, Wei; Dada, Lubna; Zhao, Jian; Chen, Xueshun; Dällenbach, Kaspar; Xie, Conghui; Wang, Weigang; He, Yao; Cai, Jing; Yao, Lei; Zhang, Yingjie; Wang, Qingqing; Xu, Weiqi; Wang, Yuying; Tang, Guiqian; Cheng, Xueling; Kokkonen, Tom V.; Zhou, Wei; Yan, Chao; Chu, Biwu; Zha, Qiaozhi; Hakala, Simo; Kurppa, Mona; Jarvi, Leena; Liu, Yongchun; Li, Zhanqing; Ge, Maofa; Fu, Pingqing; Nie, Wei; Bianchi, Federico; Petäjä, Tuukka; Paasonen, Pauli; Wang, Zifa; Worsnop, Douglas R.; Kerminen, Veli-Matti; Kulmala, Markku; Sun, Yele (2021)
    The role of new particle formation (NPF) events and their contribution to haze formation through subsequent growth in polluted megacities is still controversial. To improve the understanding of the sources, meteorological conditions, and chemistry behind air pollution, we performed simultaneous measurements of aerosol composition and particle number size distributions at ground level and at 260 m in central Beijing, China, during a total of 4 months in 2015-2017. Our measurements show a pronounced decoupling of gas-to-particle conversion between the two heights, leading to different haze processes in terms of particle size distributions and chemical compositions. The development of haze was initiated by the growth of freshly formed particles at both heights, whereas the more severe haze at ground level was connected directly to local primary particles and gaseous precursors leading to higher particle growth rates. The particle growth creates a feedback loop, in which a further development of haze increases the atmospheric stability, which in turn strengthens the persisting apparent decoupling between the two heights and increases the severity of haze at ground level. Moreover, we complemented our field observations with model analyses, which suggest that the growth of NPF-originated particles accounted up to similar to 60% of the accumulation mode particles in the Beijing-Tianjin-Hebei area during haze conditions. The results suggest that a reduction in anthropogenic gaseous precursors, suppressing particle growth, is a critical step for alleviating haze although the number concentration of freshly formed particles (3-40 nm) via NPF does not reduce after emission controls.
  • Mattila-Holappa, Pauliina; Kausto, Johanna; Aalto, Ville; Kaila-Kangas, Leena; Kivimäki, Mika; Oksanen, Tuula; Ervasti, Jenni (2021)
    PurposeAlternative duty work is a procedure that enables an employee with a short-term disability to perform modified duties as an alternative to sickness absence. We examined whether the implementation of an alternative duty policy was associated with reduced sickness absence in the Finnish public sector.MethodsTwo city administrations (A and D) that implemented an alternative duty work policy to their employees (n=5341 and n=7538) served as our intervention cities, and two city administrations (B and C) that did not implement the policy represented the reference cities (n=6976 and n=6720). The outcomes were the number of annual days, all episodes, and short-term (
  • Hemilä, Harri; Virtamo, Jarmo; Albanes, Demetrius; Kaprio, Jaakko (2003)
  • Halavaara, Mika; Martelius, Timi; Anttila, Veli-Jukka; JÄrvinen, Asko (2020)
    Background. Health care-associated infective endocarditis (HAIE) and intravenous drug use-related IE (IDUIE) have emerged as major groups in infective endocarditis (IE). We studied their role and clinical picture in a population-based survey. Methods. A population-based retrospective study including all adult patients diagnosed with definite or possible IE in Southern Finland in 2013-2017. IE episodes were classified according to the mode of acquisition into 3 groups: community-acquired IE (CAIE), HAIE, and IDUIE. Results. Total of 313 episodes arising from 291 patients were included. Incidence of IE was 6.48/100 000 person-years. CAIE accounted for 38%, HAIE 31%, and IDUIE 31% of IE episodes. Patients in the IDUIE group were younger, and they more frequently had right-sided IE (56.7% vs 5.0%; P <.001) and S. aureus as etiology (74.2% vs 17.6%; P <.001) compared with the CAIE group. In-hospital (15.1% vs 9.3%; P = .200) and cumulative 1-year case fatality rates (18.5% vs 17.5%; P = .855) were similar in CAIE and IDUIE. Patients with HAIE had more comorbidities, prosthetic valve involvement (29.9% vs 10.9%; P = .001), enterococcal etiology (20.6% vs 5.9%; P = .002), and higher in-hospital (27.8% vs 15.1%; P = .024) and cumulative 1-year case fatality rates (43.3% vs 18.5%; P <.001) than patients with CAIE. Staphylococcus aureus caused one-fifth of IE episodes in both groups. Conclusions. Our study indicates that in areas where injection drug use is common IDUIE should be regarded as a major risk group for IE, along with HAIE, and not seen as part of CAIE. Three different risk groups, CAIE, HAIE, and IDUIE, with variable characteristics and outcome should be recognized in IE.