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Although the sun is really far away from us, some solar activities could still influence the performance and reliability of space-borne and ground-based technological systems on Earth. Those time-varying conditions in space caused by the sun are also called space weather, as the atmospheric conditions that can affect weather on the ground. It is known that aviation activities can be affected during space weather events, but the exact effects of space weather on aviation are still unclear. Especially how the flight delays, the top topic concerned by most people, will be affected by space weather has never been thoroughly researched. By analyzing huge amount of flight data (~5X106 records), for the first time, we demonstrate that space weather events could have systematically modulating effects on flight delays. The average arrival delay time and 30-minute delay rate during space weather events are significantly increased by 81.34% and 21.45% respectively compared to those during quiet periods. The evident negative correlation between the yearly flight regularity rate and the yearly mean total sunspot number during 22 years also confirms such delay effects. Further studies indicate that the interference in communication and navigation caused by geomagnetic field fluctuations and ionospheric disturbances associated with the space weather events will increase the flight delay time and delay rate. These results expand the traditional field of space weather research and could also provide us with brand new views for improving the flight delay predications., Comment: submitted to science advances

Contains fulltext : 232248.pdf (Publisher’s version ) (Closed access) Radboud University, 16 april 2021 Promotores : Karremans, J.C.T.M., Kluwer, E.S. Co-promotor : Scheres, A.P.J. 183 p.

To investigate the etiology and clinical characteristics of hospital-acquired pneumonia (HAP) in China and to provide evidence for appropriate therapy.We performed a prospective multicenter study in 13 Chinese urban tertiary hospitals. All HAP cases diagnosed at respiratory general ward and respiratory intensive care unit (RICU) from August 2008 to December 2010 were studied. Epidemiological data, etiology and clinical characteristics of enrolled patients were collected. Sputum or tracheal aspirate and blood cultures, Legionella antibodies and Streptococcus pneumoniae urinary antigen tests were performed. Bacteria to antimicrobial susceptibility test was performed.A total of 610 cases of HAP were diagnosed during the study, with an overall incidence of 1.4% among 42 877 hospitalized patients, while the incidence was 0.9% (362/41 261) in respiratory general ward and 15.4% (248/1616) in RICU. 93.9% (573 cases) of patients had at least one underlying disease, and 91.0% (555 cases) had exposure to at least one antimicrobial agent within 90 days prior to HAP diagnosis. Pathogens were identified in 487 patients, with Acinetobacter baumannii [30.0% (183/610)], Pseudomonas aeruginosa [22.0% (134/610)], Staphylococcus aureus [13.4% (82/610)] and Klebsiella pneumonia [9.7% (59/610)] being the most common pathogens. Eighteen patients (3.0%) had infection with fastidious bacteria. A. baumannii and S. aureus were the more frequent pathogens in the ventilator-associated pneumonia (VAP) cases [50.5% (97/192) and 21.4% (41/192)] as compared to non-VAP cases [20.6% (86/418) and 9.8% (41/418), P0.01]. A. baumannii and S. aureus were also frequent pathogens in cases with a score of more than 20 by the acute physiology and chronic health evaluation II (APACHEII) scoring [45.7% (69/151) and 20.5% (31/151)], as compared to cases with a score of less than 20 of APACHE II [24.8% (114/459) and 11.1% (51/459), P0.01]. A. baumannii showed high resistance rates to carbapenems [more than 70% (109/142)], and the susceptibility to cefoperazone/sulbactam, polymyxin B and tigecycline were 40.8% (58/142), 99.3% (141/142) and 95.8% (136/142) respectively. Resistance rates of P. aeruginosa to meropenem and imipenem were 48.8% (40/82) and 70.7% (58/82) respectively. Methicillin-resistant S. aureus (MRSA) accounted for 87.8% (43/49) in all strains of S. aureus. Mortality rate of VAP cases was 34.5% (61/177), significantly more than that of HAP patients [22.3% (135/605), P0.05]. The average hospital stay of patients with HAP was (23.8 ± 20.5) days, significantly more than that of the average for inpatients [(13.2 ± 13.6) days, P0.01] during the study period. Mean costs of HAP were (108 950 ± 116 608) yuan, significantly higher than the average hospital costs of respiratory inpatients (17 999 ± 33 364) yuan.Among Chinese patients hospitalized in urban tertiary medical centers, HAP incidence and mortality rate were high, which increased the patients' hospital stay and the medical costs. Common pathogens were A. baumannii, P. aeruginosa, S. aureus and K. pneumonia. The common bacteria of HAP in China showed high resistance rates to antibiotics.

Our previous research showed that octacosanol exerted its protective effects in 6-hydroxydopamine-induced Parkinsonian rats. The goal of this study was to investigate whether octacosanol would attenuate neurotoxicity in 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP)-treated C57BL/6N mice and its potential mechanism. Behavioral tests, tyrosine hydroxylase immunohistochemistry and western blot were used to investigate the effects of octacosanol in a mouse model of Parkinson's disease. Oral administration of octacosanol (100 mg/kg) significantly improved behavioral impairments in mice treated by MPTP and markedly ameliorated morphological appearances of tyrosine hydroxylase-positive neuronal cells in the substantia nigra. Furthermore, octacosanol blocked MPTP-induced phosphorylation of p38MAPK and JNK, but not ERK1/2. These findings implicated that the protective effects afforded by octacosanol might be mediated by blocking the phosphorylation of p38MAPK and JNK on the signal transduction in vivo. Considering its excellent tolerability, octacosanol might be considered as a candidate agent for clinical application in treating Parkinson's disease.

Biological cilia are versatile hair-like organelles that are very efficient in manipulating particles for, e.g., feeding, antifouling and cell transport. Inspired by the versatility of cilia, we experimentally demonstrate the anti-biofouling capabilities of active surfaces that are partially covered with magnetic artificial cilia (MAC) using real biofouling agents - microalgae Scenedesmus sp. Actuated by a rotating magnet in a circular microfluidic chip, the MAC can perform a tilted conical motion, which generates strong local flow and leads to the removal of the algae away from the central unciliated area, creating a clean area.