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A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), associated with severe respiratory illness emerged in Wuhan, China, in late 2019 (1). Epidemiologic data indicate that the virus can cause a wide spectrum of clinical disease (mild-to-severe illness), including death (2-4), and spreads through direct contact and droplets.Estimates are 5-6 days (range 2-14 days) for the incubation period and 2.2-3.6 for the reproduction rate; this rate is higher than those for seasonal and pandemic influenza (5,6). Extensive control efforts are now in place as part of a global containment strategy to minimize exportation from China and rapidly identify and stop international spread.In the World Health Organization European Region, Rome, Paris, London, Istanbul, and Moscow have direct flights to Wuhan, China, and the risk for importation was considered high (7). SARS-CoV-2 was reported to have been introduced into Europe by a person from France who had traveled to Wuhan, China, for work, became ill on January 16, and returned ill to France on January 22 (8). We report a cluster of illness in a tour group from Wuhan that predates this case detection and led to subsequent transmission in Europe. The StudyA 55-year-old woman (Taiwanese tour guide) who resided in Wuhan came to airport health authorities in Taipei on January 25, 2020, complaining of a cough since January 22. She was transported to a designated hospital and showed a PCR-positive result for SARS-CoV-2 on January 26. She indicated that she had led a group of tourists from Wuhan to Europe on January 16-24. Further interviews with her and discussions with the rest of the group through social media yielded detailed information.A group of 30 persons departed Wuhan on January 16, 2020, for a 9-day tour in Italy, Switzerland, and France (Table; Figure). During the flight on January 16 from Wuhan to Rome, 1 tour member was mildly ill and coughing. Her daughter became ill during the tour on January 21.On January 23, while in Paris, the mother and daughter decided to seek medical care. They called the Chinese embassy, who told them to call the emergency hotline (at SAMU Centre 15 Hospital, Paris, France) dedicated to evaluation of suspected 2019 novel coronavirus disease (COVID-19) cases in France (8). The emergency hotline routed the call to the 24-hour ambulatory service, but no information about suspicion of COVID-19 was given. A physician came to their hotel room and gave them a diagnosis of the common cold. The interaction lasted »20 min, including a 15-minute face-to-face examination, without protective masks for

BackgroundIn February 2015 an outbreak of gastroenteritis occurred in a distillery in Kinmen, Taiwan. At least 450 affected employees developed the symptoms of diarrhea and vomiting after attending a lunch banquet on 6 February. Epidemiological, laboratory and environmental investigations were conducted to identify the agent and source of this outbreak.MethodsA case–control study was carried out among lunch attendees from the distillery. Using a semi-structured questionnaire, food and beverage consumption in the lunch banquet was assessed, as well as demographic and clinical data of the exposed people. An outbreak case was defined as a diner who developed at least three following symptoms: diarrhea, vomiting, abdominal pain, nausea, chills and/or weakness in the 72 h following the lunch. Controls were defined as lunch attendees who did not have any of the above symptoms. Rectal swabs or stool samples of the symptomatic exposed diners and food handlers as well as food and environmental samples were collected to test potential bacteria and viruses. Norovirus was detected by reverse transcription-polymerase chain reaction and sequence analysis. An environmental assessment, including environmental inspection of the restaurant and a review of work practices of food workers, was undertaken.ResultsOf 363 respondents with complete data, 169 met the case definition and 111 met the control definition. Consumption of pork liver in cold appetizers (adjusted odd ratio (aOR) 3.23; 95 % confidence interval (CI): 1.26–8.30) and lamb chops (aOR: 3.98, 95 % CI: 1.74–9.11) were each associated with increased risk of illness. No cases but two asymptomatic food handlers who prepared or cooked the implicated foods tested positive for norovirus genotype I.6. Food and environmental samples were negative for any bacteria. Environmental assessment indicated that hand washing facilities were not properly accessible to food handlers. Inappropriate hygiene practices in food handlers may have contributed to food contamination.ConclusionOur investigation suggests that etiological agent of this outbreak was norovirus. The food vehicles were pork liver and lamb chops, which may have been contaminated by asymptomatic infected food handlers. Strict adherence to hand hygiene practices and access to hand washing facilities should be reinforced to prevent such foodborne outbreaks.

A novel one-step cation exchange approach has been developed to prepare ZnO-decorated ZnSe nanorods (ZnSe-ZnO NRs), a prototype type-II semiconductor nanoheterostructure. Because of the staggered band offset which promoted effective charge separation, the as-synthesized ZnSe-ZnO NRs exhibited remarkable photocatalytic activities under visible light illumination, demonstrating their promising potentials in relevant photoconversion applications.

Laser Doppler velocimetry (LDV) measurements are presented of turbulent flow in a two-pass square-sectioned smooth duct simulating the coolant passages employed in gas turbine blades under rotating and nonrotating conditions. For all cases studied, the Reynolds number characterized by duct hydraulic diameter and bulk mean velocity was fixed at 1×104. The rotation number Ro was varied from 0 to 0.2. It is found that as Ro is increased, both the skewness (SK) of streamwise mean velocity and magnitude of secondary-flow velocity increase linearly, SK=2.3 Ro and U2+V2¯/Uh=2.3 Ro+0.4, and the magnitude of turbulence intensity level increases exponentially. As Ro is increased, the curvature induced symmetric Dean vortices in the turn for Ro=0 is gradually dominated by a single vortex most of which impinges directly on the outer part of leading wall. The high turbulent kinetic energy is closely related to the dominant vortex prevailing inside the 180-deg sharp turn. The size of separation bubble immediately after the turn is found to diminish to null as Ro is increased from 0 to 0.2. A simple correlation is developed between the bubble size and Ro. A critical range of Ro responsible for the switch of faster moving flow from near the outer wall to the inner wall is identified. For both rotating and nonrotating cases, the direction and strength of the secondary flow with respect to the wall are the most important fluid dynamic factors affecting local the heat transfer distributions inside a 180-deg sharp turn. The role of the turbulent kinetic energy in the overall enhancement of heat transfer is well addressed.

The identification of CN– in water, seeds, and biological systems has, because of its high toxicity, attracted the increasing attention of many chemical industry researchers. In the work, a novel highly selective and reversible sensor, MMY, was shown to recognize CN– effectively. The color and fluorescent changes verified the interaction of MMY with CN–, and the fluorescence lifetime of MMY was also changed upon addition of CN–. A mode of interaction of MMY with CN– based on the results of various experiments was speculated. The LOD of MMY toward CN– was 9.4 × 10–10 M, lower than the concentration of CN– deemed acceptable by the WHO (World Health Organization) and the U.S. EPA (United States Environmental Protection Agency). MMY showed good reversibility and reusability for detecting CN–. In addition, test slips and silica plates were both earned by ourselves, which were able to recognize CN– qualitatively. Additionally, MMY could recognize CN– in tap water quantitatively with the use of a smartphone APP. Interestingly, MMY was also used to detect CN– in seeds. It was valid to image CN– in Caenorhabditis elegans and mice with a vivid “turn-on” fluorescence. MMY thus can circulate in the bloodstream.

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A novel long-wavelength turn-on fluorescent chemosensor CS based on pyrene was synthesized to detect Hg2+. In the presence of other metal ions, CS could effectively recognize Hg2+ and produce the turn-on fluorescent emission at 607 nm. Also, the absorption spectrum exhibited red-shift. Meanwhile, the change of the solution color from yellow to orange was directly observed by the naked eye. The interaction between CS and Hg2+ was confirmed by the Job’s plot, electrospray ionization mass spectrometry, scanning electron microscopy, and density functional theory calculations. It was found that the fluorescence of CS could be reversible when I– was added into the solution of CS and Hg2+. CS illustrated high selectivity and good sensitivity for Hg2+ with the limit of detection of 36 nm. Moreover, CS could be utilized as test strips and silica gel plates to identify Hg2+.